IPv6 tokens are used when you want use your dynamic prefix but have a static suffix. So for example I want to a system to always end with
::dead:beef this will give me a static address to use even if/when the prefix changes! I use this on servers and other devices that I want/need a static IP but still want to reach them via IPv6.
Keep in mind that
eno1 is the name of the connection profile, which is typically named after the interface. So if you have a different interface/profile name you'll need to change it match that.
Another thing to take notice of is that eui64 is not compatible with global privacy mode. So this isn't something that you would want to enabled on something like your laptop/desktop that you're browsing the internet/gaming/etc. Unless you know what you're doing and/or want that. YMMV / Caveat Emptor / Yadda yadda…