I had a cell phone before, but it couldn't detect the SIM card. It took a long time to get it right. The next day I asked my aunt to help me with it. And the last thing I saw was I put the card upside down. Maybe your card is inserted. You can wipe it upside down or insert it the other way around. I don't know if I can use it.
If your mobile phone cannot read the card or detect the SIM card, you can try to put the card on another mobile phone to try and determine whether it is the problem of the card or the problem of the phone by changing the card and the method of changing the machine.