Verification and welcome
A math gate for new members, and a separate welcome message.
The gate
/verify setup turns the gate on and chooses the channel, the verified role, and the unverified role. New members get a short math question.
/verify sync hides other channels from the unverified role. /verify panel posts the explanation in the verification channel.
Too many wrong answers removes the member. The attempt count is part of setup.
Welcome is separate
The welcome is a custom embed when someone joins. The message content can mention them. Placeholders include {mention}, {username}, {displayname}, {server}, and {memberCount}.
Welcome does not replace verification. You can use either, both, or neither. A join that raid protection removes does not get a welcome or a challenge.