use
var firebasePlist: String? = Bundle.main.path(forResource: "GoogleService-Info", ofType: "plist")
if development == true{
firebasePlist = Bundle.main.path(forResource: "GoogleService-Info-DEV", ofType: "plist")
}
var options = FIROptions(contentsOfFile: firebasePlist)
FIRApp.configure(with: options)
but you will need to have a variable named development with a value of true if you want to use pls dev GoogleService and false if you want to use the regular tool GoogleService