What IP does GPT access my plugin manifest and openapi spec?

I am trying to incorporate IP blocking into my API endpoints and currently in the process of doing IP blocking for my plugin manifest and plugin OpenAPI spec. The IP address that it is being accessed from do not align with those suggested here in the ip egress ranges. They also are not the address of the machine I’m doing development from either. Does anybody know which ip the manifest and OpenAPI spec will be accessed from?