Honestly I have to recommend against using Proton!
I've been unable to access some of my calendars lately, which are essential for my work. It doesn't even display an error - I've just noticed that events are missing. If it was down for a few hours that'd be acceptable, but this isn't.
I've also had numerous issues with their email, the worst being that it has pretended to send emails that it hasn't, the consequences of which I had to bear. Again no error message.
And I keep hearing about them adding new features I don't need. How about spending some of that money on proper QA?
Save yourself the headache and find another provider and consider carrying a paper agenda instead. I'd also recommend using different companies for different services, as any issues will only apply to one service. It's best to have your own domain for your email so it doesn't depend on anyone.
Apparently I am free next week:
