Authenticating a license without Google Services

First I want to clarify that I don’t want to buy a license outside of the Google Play Store, I read the post about it. I don’t have a problem with buying the license from Google, but my main phone, where I want to use Symfonium, doesn’t have any Google Services installed.
My question is if I can somehow buy the license from Google and import it into the other app.
I don’t know how the whole authentication system works, but is it theoretically possible to import the license into the app through the backup function or something similar? I can pay over Google, but only on a seperate device.

I think this shouldn’t be a problem, as long as the license authentication isn’t handled by Google and the license is permanent, which it seems to be.

I really love the app and i would love to pay for a license and use it as my main music app.

No this is not possible.

What I offer now is Paypal donations of at least 6€ at to update the trialID to an infinite trial.

This is the same except a very small header in settings to remind you about it when you’ll change device and will need to contact me again.