Custom header in request

Hi,
Does Dreamfactory supports correctly custom headers in request?
Some time ago was problem with this feature: Remote Web Service and Headers
I want connect to very basic external web service. I can’t do this adding “External headers” and I can’t using ajax request.
My Ajax request:

 $.ajax({
    contentType: 'application/json',
    dataType:'json',
    type: 'GET',
    beforeSend: function (request)
        {
            request.setRequestHeader('X-Rest-ApiSign','SHA1XXXXXSIGN');
            request.setRequestHeader('X-Rest-ApiKey','XXXXXKEY');
            
        },
    url:location.protocol + '//' + location.host + '/rest/freshmail/reports/campaign/nyl6o36zfq',
    
    
    data:'app_name=Freshmailapp',
    cache:false,
    success:function (response) {
        $('#RESULTS_CONTAINER').html(JSON.stringify(response));
    },
    error:function (response) {
        console.log(response);
        alert("There was an error loading the make and model data.");
    }
});

Maybe you can give me some advice.

–EDIT–
Maybe this is connected with: URL Routing Attacks ?
I’m adding to header SHA1 string.
@stadja in their post wrote that had some problems with basic authentication.

I have tested, and headers are passed through when configured properly.

Can you confirm which headers are being received by the remote endpoint?