If you use Duplicati GUI, try the AuthID button:
To get into details which the dev might want to comment on (e.g. for release 2.2 plans):
is sending you to new C# OAuth server at https://oauth-service.duplicati.com/
At that time, Python 2.7 OAuth server at documented location could not be upgraded.
Upgrading GAE OAuth Server fixed this in January, but it still doesn’t know of pCloud.
Having Canary test pCloud on test OAuth server seems OK, but what’s coming later?
I’m kind of fuzzy on channel use before Stable, but assume prereleases will come out.
Right now, the C# MissingAuthID aims wrong, as it doesn’t know the GUI code doings.
Even without that wrinkle, arguably a user could set the OAuth server choice in option:
--oauth-url (String): Alternate OAuth URL
Duplicati uses an external server to support the OAuth authentication flow. If you have set up your own Duplicati OAuth server, you can supply the refresh URL.
* default value: https://duplicati-oauth-handler.appspot.com/refresh
and I don’t know if that’s taken into account in the message (haven’t tested the option).