How can I join the secure XFINITY and Xfinity Mobile hotspots on Ubuntu?

BUMP, on this:

https://forums.xfinity.com/conversations/your-home-network/ubuntu-laptop-how-to-join-secure-xfinity-and-xfinity-mobile-hotspots/6750e8488d87ff6f16a53b85

How can I join the secure XFINITY and Xfinity Mobile hotspots on Ubuntu (not Android)?