OTC... How does this happen?

You ask a hooker if she'll fuck you outside the club instead of in it.
The general impetus is that she keeps all the money.
If a hooker refuses its generally because what you spend on her in the club isnt worth it for her.
Its a transaction. Pay her more

The most effective way to get otc is to ask for it.
There is no secret. Not every dancer does otc. Many only do it when the rent is due or have another immediate need for cash.

Not sure how much time passed between the first and second inquiries about getting together. Now this was maybe 15 years or so ago, so not exactly yesterday.
But I once had a dancer start making out with me on the floor the first time I got dances with her/met her (in a club that wasn't wild by any means but I visited often). She initiated it and I was so shocked I don't think I tipped her all that much on top of the dances (it wasn't an extras club at all and cameras were everywhere at least out on the floor).

She wanted me to do a room either that night or in the future and I was thinking next time for sure as i didn't have a lot of cash and don't use ATMs at clubs. Anyway next time I came in (it couldn't have been more than a month or two at the most) and saw her she told me she was now dating the bouncer-AND they were getting married haha. Needless to say her regular dances were pretty terrible that night and I didn't ask about anything "extra", much less a room.

The funny thing is she really did end up marrying the bouncer and quit stripping. I went to this club for quite awhile after this (I really liked a different dancer there that was friends with this dancer that quit).

So either that dancer that made out with me was drunk or fucked up on something and was already dating the bouncer at that time-maybe he wasn't there that night too.....or she wasn't dating anyone and thought I had a ton of money and was looking to get out of the business haha (she was really hot with huge tits). She could have had any customer she wanted, but it was a dive of a club so who knows how much guys actually spent or even had at that place. I mean we are talking rough neighborhood kind of place. The two dancers/one I liked that stayed for quite awhile and the one that got married and quit were WAY above any other dancers there.

Dancers can also be very flakey to say the least so I wouldn't worry about the one being a no show. Even if they are somewhat "reliable" in the club , they aren't necessarily going to be out of it.
Just my general thoughts, I have never done OTC myself so definitely not an expert by any means.

Its not about flaking out or not being reliable. They just found a better option for their time.

First rule of asking for OTC: Depending on area and club, you'll likely get a lot more "no" responses than "yes" ones. Even after decades, I still get lots more declines than acceptances.

Second rule: Even a "yes" or "maybe" has a good chance of being just a way to get you to come back to the club and spend money, and not a real agreement.

If you really want to meet her OTC, spend a fair bit of time in the club with her, even before asking her about it, Sitting, talking, drinking, eating, whatever. Don't be stingy. Tip her on stage. If you're in a club, like many of those in Louisville, with "dancer drinks", buy her a couple. If not, slip her 10 or 20 every so often while she's sitting with you. Buy food. If she's been sitting with you for a while, "I'm gonna get some food. Do you want anything?" has been a good way to get her to sit with me for extended periods of time. Don't over do it, but don't be a cheapskate.

And if she says no, do NOT get belligerent or ignore her in the club. Remember, they get asked all the time, so even if she seems upset, be polite, and say something like "OK, if you change your mind, let me know. How about we go get a dance or two then?" If she says no, say nothing about money, even if she asks. "We can talk about that if you ever change your mind."

If she says yes, or questions what you're gonna want to do, I still don't suggest talking about money. Just be upfront and clear, "I'd like to have sex. More privately."

Some girls won't want to continue the discussion unless you do talk about money. Those are likely to be girls who do OTC regularly. If you're fine with that, go for it. I personally only do that once in a while, when I'm between regulars; I prefer girls who don't do it often if I can find them, and believe they don't. If you just want to get your nut in a place that's more private than a club, it's not a horrible place to start while you learn the ropes. Girls who do it regularly will be much more transactional than what I generally go for, e.g. if they start talking about "per hour", or "per session", or similar.

Again though, it's a place to start, just be aware that's what you're getting. One of the absolute best cocksuckers I've ever met was high as fuck volume, but she was so very worth it. She'd get me off in five or so minutes and keep going for the next 20 to 30 minutes to get me off again. Then she'd just lay there and play with me for a few minutes and do it again. Only person I've met who could routinely get me off more than once in less than about an hour.

ITC extras do not automatically imply a willingness to go outside. In fact, it can mean OTC is even less likely, unless she's really low volume. If she figures she's safe doing it in the club, she might not want to risk meeting someone she doesn't know outside. See all that stuff above about cultivating a "relationship". Hell, even if she's a firm no, circumstances can change, and she'll remember who's been nice and who's been an asshole.

Polite persistence, not pestering, spending money, and being a regular can open doors, and legs. So don't give up yet.

I'm recently converted to the world of SCs and, the way by brain works, I seek efficiency. My path quickly zeroed in on #1 goal being OTC. After trial and error, I've settled on the following techniques:
I show up decently dressed, no shorts. She asks what I do, I tell her my profession, which is known for providing a comfortable income. I am polite during the dances. The first time I always ask permission to touch boobs, even though I go to places where good contact is the norm. This all establishes that I'm a respectable member of society and lowers her guard. "What's your bf say about you working here?" "I don't have one", "How does someone so beautiful as you NOT have one?". After some good LD's, "When can I see you outside". I don't care what her answer is, I move on. This occurs while doing $80- $100 worth of dances. I'm too chicken to try these lines paying anything less. I pay up front. I get her digits.
Next time I'm at the SC, I pay upfront again. $80-$100. I ask early on when I can see her again, or when I can take her home with me. I tell her I'm in a "bit of a transition period" in my life, and am looking for "something regular and discreet". I think this is key. Why would she take on the added risk for a one-time OTC? Here, I am offering an income stream. "No pressure, the first time my goal is for you to have a great time and hopefully want to make it a regular thing. I want to find someone I can invest in instead of coming to the club... I don't to the VIP rooms cuz they're gross."
To increase your odds of success, do this at a slower club. The bar is higher at busy ones. Of bonafide attempts where I pick the girl, I'm batting about .800. This does NOT count all the girls that volunteer their services. I've NEVER taken the bait on those. If I wanted that, I can do it for less with the streetwalkers outside. I'm interested in the challenge. I've had 3 cases of 8's telling me NO for 3-4 visits and over texts "What do you think about what we talked about?", and then on the next ask, all of a sudden they change their minds. I had one girl that after multiple asks, she appeared frustrated and said "I DO have a boyfriend!", I think just to get me off her back.
Don't be creepy, don't be rough. Be the nice guy that found his muse at the SC. She will appreciated it.
Money is a weird convo and has gone several different ways. I asked one what she made in a shift to which she answered ~$300, so I offered to double it. One I offered $800, and she apologized and said $1000. She was worth every penny. The average is $800. My expectations of the arrangement (not that is matters, I guess), is a 2 hour GFE. I don't discuss the specifics. Either it comes natural for them or it doesn't. Somehow, It ususlly does.

You're on the right path, my friend. Keep on keepin' on. It may take several tries to arrange your first OTC. Once breaking through, they become much easier. After a while, girls will be contacting you to inquire about future OTCs.

A question - what kind of OTC are you looking for? A 1hr VIP type in a hotel (that you provide)? A more extended 3+ hour "date" with drinks, meal, and fun time? An overnighter?

Also, how much are you willing to spend? A dancer is usually comparing how much money she can make with you versus 8hrs on her heels with dozens of guys groping her in the club. Mid/upper-tier girls (7-8.5) usually net $250-$400/shift in the club (after door fee/tip-outs). Sometimes more if successfully selling VIPs, but often less, based on the day of the week. So, if you're willing to make it worth her time (comparatively speaking) for 3-4 hours with drinks/food in a nice setting, and you are a decent and fun dude, time with you can seem like a favorable option.

Also, always remember that she's "on the clock." No matter how much she seems to like you and be into it, fun ends when the time is up. There may be an occasional girl who simply wants to hang for a bit, but it's rare. They have sitter arrangements, baby-daddy issues, and other drama to attend to. So, YMMV.

Addendum to my previous comment: WIth Cubans, you can save a lot of time by mentioning "sugar". Not sugarbaby or sugardaddy. Just sugar. This is somehow ingrained in their culture back home as a blessing from God, so their ears perk up...

For me, the topic has been dancer initiated almost every time. But it has come after getting to know the dancer for a while.