In supergroups, my bot gets a message every time a user joins the group (by registering a MessageHandler with ~filters.private filter), so I know who it is (from the new_chat_members field) and I can kick it if it doesn't meet certain conditions (e.g. it has no username set).
However, if I put the bot in a channel, I don't get any message when a user joins it (or, at least, not by using a MessageHandler). Is it possible to get the same behavior?
Thanks