Does premium extensions with payment for streamers exists?

I’d like to develop an extension, but it requres time and backend spending. So, my idea is suitable for the broadcaster much more than the viewers.
Is there anyway to create a not freemium extension? One which the broadcaster has to pay is what I am looking for.Is that possible?

Yes.

I answered this in reply to you here

Yes. I hadn’t found the topic at that moment. Now, I’d like to close or delete this one.