JKay186
Not sure how its picking up on the 4.0.21 version, since that version isn't available in the github repo you're using. The one you're using is an archive by the way. The new one (with version 4.0.21) can be found here: https://github.com/ProtonMail/android-mail/releases
You will have to remove the current Protonmail from Obtainium before adding the new one, as the app IDs will conflict and Obtainium will say that Protonmail has already been added to the app.
Also reiterating my previous post, that Proton Pass has no APKs available on their repo, hence its not getting added to Obtainium.