code: def promote_to_admin(self, group_jid, peer_jid):
          
          log.info("[+] Promoting user {} to admin in group {}".format(peer_jid, group_jid))
          return self._send_xmpp_element(group_adminship.PromoteToAdminRequest(group_jid, peer_jid))
docs: Turns some group member into an admin
  
          :param group_jid: The group JID for which the member will become an admin
          :param peer_jid: The JID of user to turn into an admin