FCM cloud messaging API timeout - Error getting access token for service account

[padma85]

Hi,

Can someone help to provide the list of hostname and URL to be whitelisted when we call Firebase admin SDK send API to send push notification messages ? We are getting below timeout error in one of our backend server. The same service account works when i try from my local machine. So it looks more related to firewall issue. But we are not clear on the list of URL/hostname to be whitelisted as we assume the below URL internally calls other google APIs to authenticate etc.(https://fcm.googleapis.com/v1/projects/%s/messages:send)

FCM ERR: <DEADLINE_EXCEEDED><null><Timed out while making an API call: Error getting access token for service account: connect timed out, iss

 Regards,

Padma