Whitelist function IP or domain

Hi,
I have question about function domains. In function I need to call some external api which has strict access rules. I have to add domain or IP of the request source to whitelist. I see that every function has its own domain and I can call this function by this domain. I tried to add this domain to whitelist but I still have access denied.

I would like to confirm that the request is send from this enlisted domain in dashboard to narrow down where mistake is. Is the execution performed on this domain or domain is only for call to execution and it is running somewhere else?

You can add server IP

I forgot to mention that I am using cloud appwrite

You can whitelist appwrite cloud server IP

I got 5 IP addresses on lookup from https://cloud.appwrite.io, I know nothing about cloud appwrite server structure. Functions are executed on these IPs and always will be?

I played a little bit with functions and its seems that function ip is different from appwrite cloud server one and it is chaning with every new deloyment. Domain for function is only to trigger it, function itself is not executing on ip that is attached to that domain.