The only type of SIM that will respond to a ping from the Internet is an eSIM that has a Fixed Public IP tariff applied, all other SIMs are NATted and so cannot be reached from the Internet.

The only way to monitor a non Fixed IP eSIM using ICMP would be to have routers that have a VPN connection to a monitoring system or to do the monitoring from the router or some other device behind the SIM that updates a central system to confirm that they’re online (this is what we do to monitor all our Robustel routers)