Tell me, please, how can I pass an object on pure JS, without any jQuery by means of AJAX?
UPD: why does a 405 error occur?
Added to request:
xhr.setRequestHeader ('Content-type', 'application / x-www-form-urlencoded');
xhr.setRequestHeader ('Access-Control-Allow-Origin', '*');
xhr.setRequestHeader ('Access-Control-Allow-Headers', 'X-Requested-With');
xhr.setRequestHeader ('Access-Control-Allow-Methods',' PUT, GET, POST, OPTIONS ');'
But it did not help.