What are the best practices and platforms for an online study group?

This is something I tried before with a Discord group for studying Python, but it was a catastrophic failure. Lots of people showed interest, almost no one showed up at the designated time. Besides, even the one person hardly interacted.

After that, I started creating an online book/tutorial for beginners (well, anyone that is more of a beginner than me :P), but it was hard to stay motivated by myself — the whole reason for the study group was precisely to avoid that.

The topic is not defined yet (I'm thinking logic...), but I'm inclined to try it again. Streaming video and/or audio is a possibility, but not a requirement. I'd rather avoid it if possible.

Any suggestions on how to make this work?