code: def create_request_token(self, request, credentials):
          
          token = {
              'oauth_token': self.token_generator(),
              'oauth_token_secret': self.token_generator(),
              'oauth_callback_confirmed': 'true'
          }
          token.update(credentials)
          self.request_validator.save_request_token(token, request)
          return urlencode(token.items())
docs: Create and save a new request token.
  
          :param request: OAuthlib request.
          :type request: oauthlib.common.Request
          :param credentials: A dict of extra token credentials.
          :returns: The token as an urlencoded string.