I want to know too, mine is using pure iCloud

I set up a Dead Man's Switch. It sends me an email with a link every day. If I click it, I acknowledge that I am alive and nothing happens. If I do not, after a grace period and more reminders, it sends an email to my wife with a password-protected file. I have listed all our accounts, passwords, assets, etc., along with instructions on what to do and whom to ask for help.

Disclaimer: I sell digital legacy products. However, I also honestly use them, and some of these tools I distribute for free and have made open-source.

You better watch out for is 2FA, sometimes even with passwords people still get locked out, so backup codes can help.