Can't sign in Android Notebook

Can't sign in Android Notebook

I have a Mail Lite plan and am trying to configure Notebook on Android. I'm assuming since I have access via the web interface that I should also have Android access as well. Would be good to have confirmation on this to start with!

I have tried both OTP and Application-Specific passwords. All I get is "An error occured. Please try again later." I'm wondering if, since the user account has YubiKey configured, if that's somehow interfering with the sign in and if there is a known work around.

Thank you.