If you don't already have a project in Firebase you need to create one in order to generate credentials for an iOS and Android application
- Add your iOS and Android App inside Project settings.
Access project settings on top left pane next to Project Overview
- During the Add App process download the config file.
Note: For Android, having the SHA1 hash is an obligation
To get the SHA1 hash you need to generate your keystore, to generate your keystore follow this guide
You can use your debug keystore's SHA1 hash, get it by running this command inside $ROOT/android
keytool -exportcert -keystore ~/.android/debug.keystore -list -v
This should print out a SHA1 key.
IMPORTANT if you have multiple keystores (and you likely do - eg. debug and release) you'll need to get the SHA1 hashes for all of them and save the hashes to Firebase!
webClientId will be automatically generated once you create the app in the firebase console.
You can access the webClientId here. Make sure you select the correct project. webClientId should be under OAuth section.