Since this is the right crowd, for those who make money with your extension, how do you do it? I'm contemplating building an API for license checking and a simple webapp for registration / subscription management, but if anybody's using the off-the-shelf options I'd be interested to hear about your experience.
I've heard good things about ExtensionPay[1]. It didn't have what I needed at the time so I hand rolled my own on Firebase using a Stripe integration component[2]. As you probably know the issue with extensions is that the whole codebase is exposed so you need some kind of back end if you're handling payments and associated secret stores.
I'm in the process of adding payments as well and I'm starting things off with Stripe. Specifically, their payment links and subscriptions features. Longer term, I may switch, and am building things in a way that migration will be easy.
