Enable Ipv6 for Internet Connection

The Comcast system is *dual stack* by default. IPv6 should automatically be present on the WAN. Is all of your equipment IPv6 capable ? What do you get here ?;

https://test-ipv6.com/ 

I simply want to enable and provision IPv6 for my account please. I've tried calling, using the Xfinity Assistant, and it's just very frustrating. It's impossible to contact a real human and the Xfinity Assistant just wants to restart my modem over and over.