code: def add_api_stage_to_api_key(self, api_key, api_id, stage_name):
          
          self.apigateway_client.update_api_key(
              apiKey=api_key,
              patchOperations=[
                  {
                      'op': 'add',
                      'path': '/stages',
                      'value': '{}/{}'.format(api_id, stage_name)
                  }
              ]
          )
docs: Add api stage to Api key