The static IPs documented on this page (https://docs.port.io/actions-and-automations/create-self-service-experiences/security/#port-ip-addresses-for-allow-lists) should be available in the Terraform Provider as a data source.

I was burned by the addition of new IP addresses, as I had to manually curate my list. If these came from the TF Provider, I could have all my downstream stuff work automatically when the list changes.