Q:

How to use Facebook Web Hosting for my Unity Game for both WebGL and GameRoom

As can be seen from the 
Facebook's official Docs
It says that

To have both a Gameroom and a Facebook Web Game, you should leave your Facebook Web Games URL (https) unchanged. For example, https://friendsmashsample.herokuapp.com/

and also

Otherwise, if you only have a Gameroom title, you should enter https://localhost/ as shown here:

I wanted to know if there is a way to get both of them working instead of hosting WebGL game on my server and putting it's URL?
I have even tried to enable the Simple Web Hosting but the toggle just reverts Back to off upon saving.

A:

It's now fixed. 
Seems like the recent issue with Facebook various API deprecation and changes of terms and condition caused this. 

