what is issue when frontend side api call and get 504 error message in react js using axios code example

Example: axios call error handling

axios.get('/api/xyz/abcd')
  .catch(function (error) {
    if (error.response) {
      // Request made and server responded
      console.log(error.response.data);
      console.log(error.response.status);
      console.log(error.response.headers);
    } else if (error.request) {
      // The request was made but no response was received
      console.log(error.request);
    } else {
      // Something happened in setting up the request that triggered an Error
      console.log('Error', error.message);
    }

  });