simpleWebRTC with Signalmaster - allow origion

Question

My web app using the simpleWebRTC for video chat.

I deployed the signalmaster in Azure web app.

On localhost - the video chat working well.

Once I change the "SimpleWebRTC url" to point to the real server - I got an error:

"Credentials flag is 'true', but the 'Access-Control-Allow-Credentials' header is ''. It must be 'true' to allow credentials"

I defined the Azure CORS to point to specific server - for allow my origin.

What it mean "Credentials flag is 'true'" - where?

Where can I define the 'Access-Control-Allow-Credentials' header to be true?

I tried to init the server like this:

server = http.createServer(function(req,res){
    // Set CORS headers
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Credentials', 'true');
...

Thanks