code: def unban_chat_member(
          self,
          chat_id: Union[int, str],
          user_id: Union[int, str]
      ) -> bool:
          
          self.send(
              functions.channels.EditBanned(
                  channel=self.resolve_peer(chat_id),
                  user_id=self.resolve_peer(user_id),
                  banned_rights=types.ChatBannedRights(
                      until_date=0
                  )
              )
          )
  
          return True
docs: Use this method to unban a previously kicked user in a supergroup or channel.
          The user will **not** return to the group or channel automatically, but will be able to join via link, etc.
          You must be an administrator for this to work.
  
          Args:
              chat_id (``int`` | ``str``):
                  Unique identifier (int) or username (str) of the target chat.
  
              user_id (``int`` | ``str``):
                  Unique identifier (int) or username (str) of the target user.
                  For a contact that exists in your Telegram address book you can use his phone number (str).
  
          Returns:
              True on success.
  
          Raises:
              :class:`RPCError <pyrogram.RPCError>` in case of a Telegram RPC error.