Loading different GoogleService-Info.plist for dev and prod environments

README.md

If the builds are part of a single target, the best option is to give both configuration files unique names (e.g. GoogleService-Info-Free.plist and GoogleService-Info-Paid.plist). Then choose at runtime which plist to load. This is shown in the following example:

// Load a named file.
let filePath = Bundle.main.path(forResource: "MyGoogleService", ofType: "plist")
guard let fileopts = FirebaseOptions(contentsOfFile: filePath!)
  else { assert(false, "Couldn't load config file") }
FirebaseApp.configure(options: fileopts)

See here for Firebase documents for more information