Error Digital Editions encountered an error while activating.

Device: iPad

OS: iPadOS 15

App: Adobe Digital Editions

Steps:

1. Install app

2. Go to Settings

3. Tap "Authorize"

4. Enter username and password

5. Wait...

6. Alert box pops up with the error message (no error code):

"Error - Digital Editions encountered an error while activating."

7. Contact Adobe support, that tell me that Digital Editions is not supported

8. Post here.

9. Pray that someone have an answer...