These roles are unpaid — no salary, no stipend, no equity. We'd rather say that plainly on the page than let you find out on a call after you've written an application.
What we're actually offering is the thing that's hard to get on your own: a live product, real users, and work that someone will hold you to. If that trade isn't worth it to you right now, that's a completely reasonable call, and we'd rather you made it before applying than resent it after.
We'll put the arrangement — scope, hours, how long, and what you're free to publish — in writing before you start, so there's nothing to be surprised by later.