Iphone XR unable to activate after updating to IOS 18

My XR recently updated to IOS 18 automatically and it somehow reset my iphone and I'm back to the set up screen. But after configuring the network, screen says unable to activate - an update is required to activate your iphone. I tried restarting the device, tried connecting to itunes on my Windows laptop but I get the same error - Iphone could not be activated because the activation information could not be obtained from the device. My sim doesn't work either. I don't think my phone can detect the sim card even when it's properly inserted.