Firewall rules for outgoing traffic from gorush to fcm

[mkuznetsov]

https://firebase.google.com/docs/cloud-messaging/concept-options#messaging-ports-and-your-firewall

This list is for incoming push messages to user devices behind firewall. I need list for gorush push sender.
My gorush server is behind firewall and I need a list of domains to send push messages to FCM. Right now I get some from different sources, but It don't work and in logging I don't get domain names I stuck with. Ports 443, 5228-5230 opened. Can you add log messages for domain name gorush get timeout or answers with errors?

my current list for outgoing domains for push traffic from gorush to FCM is this:
-fcm.googleapis.com,
-www.googleapis.com,
-account.google.com,
-oauth2.googleapis.com.

where can I get list needed for gorush to function? I don't find FCM doc for this topic yet.