Facing SIM card failure issue on my iPhone

janisw wrote:

My iphone is no longer cellular. It states a sim card failure and will only turn on in SOS mode

if a physical SIM take it out and reinsert it.

Remove or switch the SIM card in your iPhone - Apple Support

ref

If you see SOS, No Service, or Searching on your iPhone or iPad - Apple Support

if no resolve talk to your carrier—

Set up cellular service on iPhone Setup eSIM

Set up cellular service on iPhone - Apple Support

put your iPhone in diagnostics mode - identify potential hardware and software issues

How to put your iPhone in diagnostics mode - Apple Support

You can muddle your way through the support document if you want, but not much is going to happen until you contact your carrier and ask them to send you a new SIM card.

Or, if your carrier has a store nearby, drop by the store.