Example of how to get ajax call in a synchronous way

ajax-synchronous.js

let url = 'https://jsonplaceholder.typicode.com';
let buttonAjax = document.querySelector('.buttonAjax');

buttonAjax.addEventListener('click', doSomething);

function doSomething() {
  console.log('do something more...');
  return getAjax(callback, 'users', anotherAjax);
}

function getAjax(callback, webservice) {
  $.ajax({
    type: 'GET',
    url: `${url}/${webservice}`,
    // dataType: 'json',
    // data:  {},
    success: function(data) {
      return callback(data, anotherAjax);
    },
    error: function(error){
      return callback(error);
    }
  });
}

function anotherAjax(callback, webservice) {
  $.ajax({
    type: 'GET',
    url: `${url}/${webservice}`,
    // dataType: 'json',
    // data:  {},
    success: function(data) {
      return callback(data);
    },
    error: function(error){
      return callback(error);
    }
  });
}

function callback(data, nextAjax) {
  // Ajax nested
  if (nextAjax) {
    return nextAjax(callback, 'users?id=1');
  }

  console.log(data)
  return data;
}

https://jsonplaceholder.typicode.com/
https://stackoverflow.com/questions/39067752/javascript-function-ajax-call-returns-undefined
https://stackoverflow.com/questions/17802211/ajax-call-returning-undefined