Check Upgrades -> Software Upgrades in the Tesla app. (I already have FSD, so I don't see it there, but it's my understanding that this is where it should be.)
That said, IMHO the FSD features aren't worth the $12,000 that Tesla is currently asking, much less the $15,000 that it'll cost in a few days. FSD-on-city-streets is more difficult than regular driving, because FSD is really flaky student driver functionality -- you have to watch traffic, plan what you want to do, etc., and then when (not if) the car does something other than what you plan, decide instantly whether what it's doing is reasonable or reckless, and intervene in the latter case. In my experience, this takes more mental effort than normal driving. It's also, IMHO, not yet safe. I use it only in light traffic, on simple roads, and when I'm feeling generous towards Tesla.
It may be better in the future, but even then, I'm skeptical that it'll be worth $15,000+, or even the $12,000 that it costs now. That sort of money will pay for a lot of Uber/Lyft/taxi rides. Tesla's been promising functionality better than it's providing now for years, and it's always "just around the corner." At this point, they need to deliver much better than they have before they can justify a price increase. My suspicion is that, by the time they do, other vehicles will have similar functionality at lower prices, and the price of FSD on Teslas will collapse. That's just my suspicion, though. I offer a full refund of the $0 you paid me for it if I'm wrong.
FWIW, I bought FSD in early 2019, when I bought my Tesla. At that time it was just $5,000. I have yet to get my $5,000 worth, although I have gotten some value from my FSD purchase, since at the time, that was the only way to get what's now sold as Enhanced Autopilot. Those features, although not worth the $6,000 that Tesla now wants for them, do have positive value, unlike FSD, which today has negative value -- Tesla should be paying people to beta-test this feature set, not the other way around.