Send PUT from pure Javascript to Laravel controller

i try to send data via PUT method, but Laravel 5.5 do not see any data inside Input (or Request) on destination controller.

Here JS:

    function selectProject(option){

        console.log('Update selected');

        var data = new Object();
        data.project_id = option.value;
        data.user_id ={{auth()->user()->id}};
        console.log(data);

        var url = "/admin/projects";
        var xhr = new XMLHttpRequest();

        xhr.open("PUT", url+'/update_selected', true);
        xhr.setRequestHeader("X-CSRF-TOKEN", "{{ csrf_token() }}");
        xhr.onload = function () {
                var response = xhr.responseText;
                if (xhr.readyState == 4 && xhr.status == "200") {
                        console.log(response);
                        document.getElementById("app").innerHTML = response; 
                } else {
                        console.log(response);
                        document.getElementById("app").innerHTML = response; 
                }
        }
        xhr.send(data);
    }

inside Laravel controller i try to showing inputs:

    echo '[Controller]Inputs:';
    return Input::all();

Here output from console.log:

Update selected
{…}
 project_id: "4"
 user_id: 1
 __proto__: Object { … }
[Controller]Inputs:[]

Question: what i'am doing wrong and where is inputs data? p.s. I can use only pure javascript, no jQuery or anothers.