I'm trying to give role to a member after inviting 2 members to the server or have 2 or more invite uses, I'm uncertain if I used the correct event

  1. on_ready() will only execute on bot startup. What you want is probably on_member_join(member).
  2. You can't get the invite by doing member.invite, as discord.Member objects does not provide it.
  3. Member.add_roles() takes a list of roles, not a single role.

A solution to your problem could be to register each invite in a dict, then compare each of them when a member joins.