code: def groups_invite(self, *, channel: str, user: str, **kwargs) -> SlackResponse:
          
          self._validate_xoxp_token()
          kwargs.update({"channel": channel, "user": user})
          return self.api_call("groups.invite", json=kwargs)
docs: Invites a user to a private channel.
  
          Args:
              channel (str): The group id. e.g. 'G1234567890'
              user (str): The user id. e.g. 'U1234567890'