Can’t add a new Facebook admin to a page by email – not found in 2023

Even using the email they registered with on Facebook, sometimes you can’t find them to add them to a page if you aren’t friends and only have their email.

Try using their username instead, i.e. go to their profile page and where it says

https://www.facebook.com/their-username123

Copy their-username123

Go to your page -> Settings (on the left)

Click on New Pages experience

Select Page Access

Click Add New and Okay

Paste their name, and voila!

Also try getting them to check they have liked the page if you still don’t see them!