recently traveled, swapped my normal sim for a loc sim but since i’ve switched bck to my regular sim i keep getting this msg ‘you must have sim associated with an apple device’ wont let me use my number for imessage plz help i’ve tried everything

It sounds like your iPhone might still be trying to authenticate iMessage and FaceTime using the previous SIM card information. Let's try a few steps to help resolve this:

1. Turn Off iMessage and FaceTime: Go to Settings > Messages and turn off iMessage. Also, go to Settings > FaceTime and turn off FaceTime.
2. Restart Your iPhone: After turning off iMessage and FaceTime, restart your iPhone. Hold down the power button until the "Slide to power off" slider appears. Power it off, then turn it back on.
3. Reset Network Settings: Sometimes, resetting network settings can help. Go to Settings > General > Reset > Reset Network Settings. This will reset Wi-Fi networks and passwords, cellular settings, and VPN settings.
4. Check Date & Time Settings: Ensure that your date and time settings are correct. Sometimes, incorrect settings can cause issues with iMessage activation.
5. Sign in Again: Sign back into your Apple ID in the Messages and FaceTime settings using your phone number. Go to Settings > Messages > Send & Receive and make sure your phone number is selected.
6. Contact Apple Support: If the issue persists, it might be necessary to contact Apple Support directly. They have more advanced tools to diagnose and resolve these issues.
7. SIM Card Check: Ensure that the SIM card is inserted properly and that it's not damaged in any way. A damaged SIM card might cause authentication issues.

After trying these steps, if the problem still persists, reaching out to Apple Support would be the best course of action. They can guide you through more advanced troubleshooting steps specific to your situation.

To activate iMessage and FaceTime using your Phone number

1. First, check to know whether you have an SMS plan enabled for at least One SMS*** with your carrier. Contact your Carrier (Cellular Service Provider) the agency that issued the SIM to you
2. If your iPhone is used with a carrier not found in the wireless carrier articles, make sure you can send and receive international SMS. (One international SMS*** Only)
3. If you can't turn on or sign in to iMessage or FaceTime - Apple ...

*** You may not have an SMS plan (Domestic & International) enabled by your carrier for the SIM/eSIM that you use on your device. Apple Inc does not provide SMS services.