"Can I use the MyFairphone app on an alternative operating system like /e/OS?
No. The MyFairphone App depends on some Google Play Service APIs. So the phone needs to have Google Play Services installed. The MyFairphone App currently does not work with operating systems other than the Fairphone OS. However, we are looking into the possibilities to make it available in the future."
(https://support.fairphone.com/hc/en-us/articles/4421671429009-MyFairphone-App)