If your SIM card is not working, you can try the following steps:
1. Restart your phone: Sometimes, simply restarting your phone can fix the issue.
2. Check the SIM card: Make sure the SIM card is inserted correctly and clean any dust or debris that may be on the card or in the SIM card slot.
3. Try the SIM card in another phone: This will help determine if the issue is with the SIM card itself or with your phone.
4. Contact your mobile carrier: If none of the above steps work, contact your mobile carrier to see if they can provide a replacement SIM card or troubleshoot the issue further.