Have you tried gols on desktop ? Garmin on linux sucks...
https://medium.com/@euri10/gols-garmin-on-linux-sucks-f1f065f7529a
It can upload activities and daily monitor, no download.
Possibles issues:
You have to mount your watch on the phone (I don't know how to)/send fit files over bluetooth (I'm stil trying to pair the phone with my car )...
I'm pretty sure ubports can run python scripts ( as gols is)...
Once you solve the issues you are done qith tracking info.
But, I don't know nothing about notifications.
Salut!