oh ok, didn't know. still, all I wanted to say is it's a cool feature. and Proton has up to 10, firefox up to 5 I think.
What I like about Proton Pass is the aliases for your email, they are one of the neatest features I have seen in the last time, even firefox now has that feature
I think Proton bought SimpleLogin or something. It's very similar, I use both to have more free aliases