IP addresses on inbound webhook requests

I have a SmartApp hosted by a cloud provider and need to configure firewalls rules such that the inbound ports used for ST webhook calls are not open to the entire internet. Can you please provide the address blocks used by ST to generate webhook requests to enable configuration of restrictive firewall rules which allow only requests from ST

Thanks

Not sure if there are IP block addresses available, but you should only need TCP port 443 for HTTPS traffic open.