imessage and facetime not working

A Mobile has no control over iMessages and/or Facetime as these are Apple services.

However, when attempting to activate either service, Apple sends a text in the background to your phone in order to verify you are the owner of said number and it’s likely that this process fails. I recommend that you perform a network reset on your iPhone.

• If you're using iOS or iPadOS 15 or later, tap Settings > General > Transfer or Reset [Device] > Reset > Reset Network Settings.
• If you're using iOS or iPadOS 14 or earlier, tap Settings > General > Reset > Reset Network Settings.

Hi @GS10 

Please try the following;

1) Turn off iMessage (Settings > Messages)
2) Restart your phone (by pressing and holding the on/off button)
3) Tap Settings > Phone > My Number and confirm that it is correct. 
4) If it is not correct, please enter the correct number
5) Turn iMessage back to On (Settings > Messages)
6) Finally, go to Settings > Messages > Send & Receive and see if the correct number is displayed under "Start new conversations from:"

If you are having issues with the above please retry with flight mode enabled and/or the SIM card removed.
 

Tom