With the release of the desktop apps, Proton Mail is now available on all major desktop and mobile platforms, offering over 100 million people worldwide a private alternative to Big Tech, regardless of their device.
I use Firefox, but I have to use a different browser for PWAs, it sucks. If I'm lucky, Epiphany works with that website, otherwise I have to use some Chromium browser. Bleh.
I did that for a while but the links in the PWA kept opening in that browser instead of Firefox. That's why I prefer to use Electron apps, because links open in FF.