SIM card not working

See the following Apple articles:

If you can't activate your iPhone

https://support.apple.com/en-us/HT201407

How to unlock your iPhone for use with a different carrier

https://support.apple.com/en-us/HT201328

👉🏼 Your cellular service provider is responsible for the SIM card and they are responsible for providing the correct one for your iPhone.

Better yet, see if you can activate the built-in eSIM. 😉