w: OAuthFlow = self.app.oauth_flow
                bolt_req: BoltRequest = to_bolt_request(event)
                query = bolt_req.query
                is_callback = query is not None and (
                    (_first_value(query, &#34;code&#34;) is not None and _first_value(query, &#34;state&#34;) is not None)
                    or _first_value(query, &#34;error&#34;) is not None
                )
                if is_callback:
                    bolt_resp = oauth_flow.handle_callback(bolt_req)
       