@khabazkameel please use this code (replace anything in JavaScript code with this)
//--------- Web ---------
OneSignal.push(function() {
OneSignal.getUserId(function(userId) {
console.log(“OneSignal User ID:”, userId);
// (Output) OneSignal User ID: 270a35cd-4dda-4b3f-b04e-41d7463a2316
bubble_fn_1(userId)
});
});//--------- Web ---------
for web ONLY.
I have tested now and I can successfully register both IDs, but when I am registering the second one it will delete the first and I need to investigate this. Again, I need some time off so this should help you use it for web ONLY.
I will fix it …this year 
so it can use both mobile and web.