code: def register_account(self, username, service):
          
          data = {
              'service': service,
              'username': username,
          }
  
          return self._perform_post_request(self.register_account_endpoint, data, self.token_header)
docs: Register an account against a service.
          The account that we're querying must be referenced during any
          future task requests - so we know which account to link the task
          too.