My phone is not connecting to network

"My phone is not connecting to ios: It’s saying no sim card"

-------

Troubleshooting "No SIM":

A. If "No SIM" shown on the top-left corner of your screen, go here to fix that: If you See 'Invalid SIM' or 'no SIM' on your iPhone or iPad - Apple Support

B. Whom to Contact:

Contact your Carrier, as their are the one who provide you with the service of configuring the SIM c