App issues
Why can’t I download apps signed in to my Apple ID
iPhone 12, iOS 14
What happens when you try? Error message(s)? More information would help.
See the Apple Support article(s) below.
App Store, iTunes Store, or other Apple services - If you can't connect
Some things you can try. Do you have access to another WiFi network where you can try? That has worked for several people.
Try a restart.
Restart your iPhone, iPad, or iPod touch
Try a forced restart.
If necessary
Do a backup and try a factory reset. Then restore from your backup.
Backup - Restore your device from an iCloud or iTunes backup.