WEBGL? Can not find it

I tried to view an item and it said 3D not available in your browser. Go to Pref, click on this, Go to Adv click on this, and then go enable WEBGL… that is not shown anywhere on the Dev site. How do I find it so I can enable it? I am running a Mac with El Capitan. Thanks

https://get.webgl.org/

Does is work on Safari?