According to the Andy Yen, CEO of Proton, Proton does not support Monero in any way and will probably never offer a Monero payment nor a Monero wallet. They don’t want to be associated with criminals, they’re afraid of the government putting a target on their back, like with Tornado Cash or Samourai Wallet, and there are auditing requirements in Switzerland that prevent them from accepting Monero.
There is really no good reason to use Proton at this point. They are trying to become the crappier alternative to Google and Microsoft with the goal of providing “privacy”, yet they fork over data on demand and go the opposite direction of the privacy community.
If you want email, self-host with Modoboa, Maddy, Mail-in-a-Box, iRedMail, or any of the other open-source mail servers.
If you want productivity tools, use LibreOffice. If you want it on a server, spin up a linux server and install Nextcloud with Nextcloud Office.
If you need a monero wallet, use the monero wallet cli, monero gui, feather wallet, or cake wallet.
If you want to save passwords, use KeePassXC and store them on an encrypted container.
If you want to exchange coins, there is a table of options on dread: http://dreadytofatroptsdj6io7l3xptbet6onoyno2yv7jicoxknyazubrad.onion/post/9102fba1f90b5df1e0f5
With all that said, fuck Proton!
Podcast: http://optoutkoplzfgs7wl3gkg5nmtrrs7ki6ljcguf7c4w7rdsrtozlghxad.onion/episodes/protonwallet-andy-yen/