What I'm trying to do: HTTP messaging to my android app
Rails server on AWS -> HTTP request to Firebase with fcm gem -> HTTP Response
In this flow, what port should I open to Firebase server?
I've opened 5228~5230 as FCM docs said, but it didn't work. (My server retunrs 500, execution expired error) Only when I open all ports open to whole world, it worked.
What ports should I open..?