I had to deactivate my Adobe ID's two-factor authentication in order to log into Adobe Digital Editions. Adobe should update the program to support two-factor authentication. The only reason I even need the app is to read a borrowed eBook from my school library for a research project, I shouldn't have to disable a security feature on my personal Adobe account in order to do so.
Not sure this is still relevant, at least: here you find instructions using older Adobe apps (which still not support 2FA) with your 2FA enabled. https://helpx.adobe.com/de/x-productkb/global/2-step-verification-account-security.html
In a nutshell: type your password followed by ":" and then the current 2FA code. Worked well for me.
This totally worked for me, so it is very relevant, thank you for sharing. password:TOTP worked in latest Adobe Digital Editions version on macOS.