(Guix GNU+Linux) Need help with packages with older versions than wanted on the Guix Channel.

Hello. I am new to the Guix GNU+Linux distro. And I’m trying to get the latest version of Anki (2.1.65). However, an older version (2.1.16) is what's there in the Guix channel (which is too old). I’m reading here that a simple edit to the education.scm file (the version var) would fix it. Unfortunately, the education.scm file in a Guix system is readonly. Unless the guix git repo maintainers update the code, my only option is to make a custom module and package to supply a newer version. Though, I don’t know how to do that (I’m a noobie). I just need help on figuring that out. Any help is appreciated.