Thanks for your great post! Really helped me!

Still good for early 2025 :p

A few words on iOS:

• you must have a dedicated firebase ios app inside your project (then add .plist to the root folder of your expo app)
• you need to setup an APNs key from an apple dev console (just google "firebase push notif to ios" and follow firebase tutorial)
• as you need to "convert" APNs token to FMC token you should use react-native-firebase/messaging to fetch a fcm token from an iOS device (https://rnfirebase.io/messaging/usage)
• the playload is slightly different from android but it's well documented in the firebase sdk