I finally managed to write the source code for a TG game bot and added invitation-based registration.
Then, when testing it, I added 100 invitation codes. It turned out there was a bug, so I couldn’t use them. After I finished testing, I wanted to invite people—but the invitation codes were gone. Turns out there was another bug: whenever someone used an invitation code, it destroyed all the invitation codes… I’m speechless. I’ll fix it again later.