구글 로그인 에러가 납니다.

강사님의 타이핑 치시는대로랑 https://pub.dev/packages/firebase_auth#-readme-tab- 공식 라이브러리 대로 둘 다 해봤는데 아래와 같이 오류가 납니다.

E/flutter (20218): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 12500: , null)

E/flutter (20218): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:564:7)

E/flutter (20218): #1      MethodChannel.invokeMethod (package:flutter/src/services/platform_channel.dart:302:33)

E/flutter (20218): <asynchronous suspension>

E/flutter (20218): #2      GoogleSignIn._callMethod (package:google_sign_in/google_sign_in.dart:226:58)

E/flutter (20218): <asynchronous suspension>

E/flutter (20218): #3      GoogleSignIn._addMethodCall (package:google_sign_in/google_sign_in.dart:268:20)

E/flutter (20218): #4      GoogleSignIn.signIn (package:google_sign_in/google_sign_in.dart:339:48)

E/flutter (20218): #5      LoginPage._handleSignIn (package:instagram_clone/login_page.dart:43:64)

E/flutter (20218): <asynchronous suspension>

E/flutter (20218): #6      LoginPage.build.<anonymous closure> (package:instagram_clone/login_page.dart:28:19)

E/flutter (20218): #7      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:511:14)

E/flutter (20218): #8      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:566:30)

E/flutter (20218): #9      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:166:24)

E/flutter (20218): #10     TapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:240:9)

E/flutter (20218): #11     TapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:177:9)

E/flutter (20218): #12     PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:436:9)

E/flutter (20218): #13     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:73:12)

E/flutter (20218): #14     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:101:11)

E/flutter (20218): #15     _WidgetsFlutterBinding&BindingBase&GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:221:19)

E/flutter (20218): #16     _WidgetsFlutterBinding&BindingBase&GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:199:22)

E/flutter (20218): #17     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:156:7)

E/flutter (20218): #18     _WidgetsFlutterBinding&BindingBase&GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:102:7)

E/flutter (20218): #19     _WidgetsFlutterBinding&BindingBase&GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:86:7)

E/flutter (20218): #20     _rootRunUnary (dart:async/zone.dart:1136:13)

E/flutter (20218): #21     _CustomZone.runUnary (dart:async/zone.dart:1029:19)

E/flutter (20218): #22     _CustomZone.runUnaryGuarded (dart:async/zone.dart:931:7)

E/flutter (20218): #23     _invoke1 (dart:ui/hooks.dart:233:10)

E/flutter (20218): #24     _dispatchPointerDataPacket (dart:ui/hooks.dart:154:5)

E/flutter (20218): 

구글링 해봐도 뾰족한 수가 없어서 질문으로 남깁니다.