How to display the PHP error message in JavaScript?

The problem is that to get the php data, if there is an error in php it shows an error like this:

What I want is to know how to show that error in the browser console.

I have this snippet of code in javascript using angularjs

var app = angular.module("ejemplo",[]);

app.service("ejemploSrv", function($http) {
  this.getEjemplo = (onResponse, onError) => {
    $http.get("http://localhost/ejemplo.php").then(onResponse, onError);
  }
});

app.controller("ejemploCtrl", function($scope, ejemploSrv) {
  ejemploSrv.getEjemplo((onResponse) => {
    //Si no aparece el mensaje de error de php
  }, (onError) => {
    //Si hay error en php
        console.log(JSON.stringify(onError.data));
        console.log(JSON.stringify(onError.status));
        console.log(JSON.stringify(onError.statusText));
  });
});

In the example I show in the console 3 data if there was an error in the request, which shows me undefined