I installed the public beta on a test iPhone 7. On my Iphone X with 12.3.1. I have the Apple logins for a few relatives and use the Find My Phone app to locate them as needed. Can I locate these users with the new Find My app and these users running 12.3.1 on their devices and if so, how do I do this? I tried adding one user to be able to see me, but they did not receive any notification and I can't see myself from their phone.