how do i block my iphone when stolen

my phone was stolen to how can i report the serial nmber where they dont have this site on how to block the phone was stolen

Use the Find my iPhone feature, either through another iOS device or the iCloud webpage.

Only the carrier can block the device from their network.

Apple does not block devices, they are not law enforcement.

Report the lost/stolen device to local law enforcement.

Apple does not maintain a list of stolen devices.