App crashing when using Firebase Auth, reason: 'Default app has already been configured.'

Question

I\'m building my first iOS application, and I am using Firebase to handle authentication, database, etc. I added a sign up screen and used the following code to create a new

Answer 1

Class Name: AppDelegate+FCMPlugin.m

[FIRApp.configure()];

Put this at the top most of this method

- (BOOL)application:(UIApplication *)application customDidFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
 if(![FIRApp defaultApp]){
    [FIRApp configure];}}