iOS 14 - Call blocking and Identification is missing?

Which app did you delete?

Not showing this option in my I phone x iOS 14.3

already did it, it appear back. but in 3-4 days this menu dissapeared again, and i must re do this step again

using whoscall and truecaller

The only native option on iPhones running iOS 13 or later is to Silence Unknown Callers, as per this support article:-->Detect and block spam phone calls - Apple Support

If you're talking about a 3rd party app you downloaded from AppStore, contact that app's developer team.

Regards

Giulio

Delete the app you’re using to identify spam via Settings, General, iPhone Storage.

Do a 3 step “hard reset” (volume up, volume down, then hold down power button until phone shuts down automatically.)

Note: Do not perform this while phone is charging!

Reinstall the app

Good luck!