JSquared2 said: "There's also Cameo (and Only Fans). Also quite a few chorus boys (and girls) have sugar daddies."
I haven't come across any "popular" musical theater performers with an OF, but I'm not super invested in that world so I guess it'd be easy to miss for me anyways haha
These days, I find that many actors adopt side hussles where they can be flexible and make their own work.
Matt Doyle embodied this pretty well as he was a fitness instructor at Barry's Bootcamp and has his Twitch feed. Tons of trainers and class instructors at Equinox and NYSC are performers. Many others have adopted a Youtube channel and/or podcast connected to their own side business. I know a bunch who have alost gotten their real estate licences.