I tried every tip and every option to use the anonymous login to download apps, but it fails e-ve-ry-time. I’m getting really frustrated about it.
Yes… I close my VPN;
Yes… all settings are alright;
Yes… I can login with a temporary Gmail account, but that’s NOT the solution.
What more can I do ?
Give me your golden solution and I let you punch Trump right in his face.
Thank you.
Regain your privacy! Adopt /e/OS the deGoogled mobile OS and online services
The one thing you did not mention is Try again later !
Actually you don’t mention Clear storage, this is the first to try.
This is the App Lounge F.A.Q.
Thank you for your reply Aidb, but like I mentioned… tried it all.
Also clear cache and clear storage.
Renew session… a thousand times.
But… I’ll try it again… later 
See
A possibility which I noticed on my device was:
Before I set this, it didn’t work to use anonymous login with App Lounge, it always aborted or displayed errors, even after logging out and trying it again multiple times.
This was wholly independent of the fact that I only wanted to download free applications out of the Google Play / App store (which were not existing in F-Droid), it didn’t even load without errors.
After I configured the “Settings” => “System” => “microG” => “Google device registration” to:
Register device => enabled
Select profil => Native (not automatic: native)
And under Google accounts I configured
“remove device name for authentification” => disabled
“Allow apps to find accounts” => disabled
“Trust Google on app right management” => disabled
“Authentificate with device registration” => enabled
… it worked without any flaws for me, even without actually entering a Google account in microG.
I still used App Lounge as anonymous login, as well.
This won’t be usable if you want to pay/buy apps from the store with a real account, but if you just want to use an anonymous account to download free apps, maybe it helps.
(The descriptors could be slightly differently named in English, I translated them from my native language. But it should be identifiable.)