12. ChatGPT에게 물었습니다.auth.signInWithPopup(provider)를 설명해줘Please explain auth.signInWithPopup(provider)ChatGPTauth.signInWithPopup(provider) is a method provided by Firebase Authentication for signing in users using a popup-based OAuth authentication flow. This method is commonly used to authenticate users with third-party identity providers like Google, Facebook, GitHub, and others. The provider ..