signInWithApple method
Implementation
Future<UserCredential?> signInWithApple() async {
//get generated nonce
final rawNonce = _generateNonce();
//encrypt nonce
final nonce = _sha256ofString(rawNonce);
//initialize apple credential
final AuthorizationCredentialAppleID appleCredential =
await SignInWithApple.getAppleIDCredential(
scopes: [
//set scopes
AppleIDAuthorizationScopes.email,
AppleIDAuthorizationScopes.fullName,
],
nonce: nonce,
);
//set credential
final oauthCredential = OAuthProvider("apple.com").credential(
idToken: appleCredential.identityToken,
rawNonce: rawNonce,
);
//sign in with credential
return await Utils().signInWithCredential(oauthCredential);
}