How Can I Add a Background Image for FirebaseUI Login for iOS?
问题 I'd like to be able to place a background image behind the three sign-in buttons (for Google, Facebook, and Email) of the FirebaseUI login screen. FirebaseUI login is a drop-in authentication solution for iOS, Android, and Web. I'm having trouble with iOS. There's a little bit of advice on Github, but not enough. I first initialize my var customAuthPickerViewController : FIRAuthPickerViewController! near the top of the ViewController.swift file. Then, this is the function in my ViewController