Failed to obtain FCM Token

[Virgus]

Hello, very interesting project. I'm struggling to test it but I'm getting the message "Failed to obtain FCM Token".

Here the steps I've done so far:

1. Downloaded and installed the apk from the GitHub repo.
2. Enabled permissions (SMS, Phone, Camera) for the apk
3. Registered on the web site and clicked "Get Started" button
4. Got the api key via the QR code scanning
5. Selected the default SIM

Then I've been trying several times by clicking around but I've no clue what's missing. Could you please point me to the right steps ?

Thanks and have a nice day, V.

EDIT: BTW I cannot see any Device ID in the app GUI. I'm using Lineage OS Android 11 version. Might this be the cause of what's going on ?