The best route would be deleting these accounts since they may have very private information that’s no one else’s business. One way to make this clear is to say: “I’m giving you access to my phone but I’d appreciate it if you didn’t read my texts because I wouldn’t want you to do that when I was alive.”
There’s also a matter of deleting any video conference platforms, like Zoom and RingCentral that have become vital communication tools during COVID. If primarily use Google, Facetime, or Teams those should go with the details about your Google, Apple, or Microsoft accounts, respectively.
Identify all the messaging and videoconferencing services you use, what needs to be deleted, and how to cancel them. This is also a good time to revisit the task about sharing the unlock code for phone and computer; include instructions about texts and other types of communication you may want deleted.
If you use a password manager you can write it directly in the notes field, if you use a digital document you can put it there, and last but not least you can put it in the Digital Accounts section of your Everplan.