ID still greyed out on iPhone 7, how do i get this back so i can change things?

Have you checked Settings/Screen Time for any restrictions?

Do you have access to another WiFi network where you can try? That has worked for several people.

Try a forced restart.

Reset Device.     

If necessary

Hard reset.        

If there are restrictions in Screen Time that are preventing access, you will need to restore the device to factory settings. Do not restore from a backup made when the Screen Time code was active.

If there aren't any Screen Time restrictions, do a backup and try a factory reset. Then restore from your backup.

Restore to Factory setting.      

Backup - Restore your device from an iCloud or iTunes backup.     

I can't guarantee a fix, but see:

Why is my Apple ID setting greyed out on iPad? https://discussions.apple.com/thread/8355468

Apple ID banner grayed out https://discussions.apple.com/thread/8611970

My Apple ID is Greyed Out in Settings, Fix https://macreports.com/my-apple-id-is-greyed-out-in-settings-fix/

You are welcome.