Keep getting the error Google Sign-In Error: PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 10: , null, null)

I'm trying to implement google sign-in for my app without firebase. I seem to have done all the steps suggested in the documentations, and for other answers, but i still keep getting this error:

Google Sign-In Error: PlatformException(sign_in_failed, com.google.android.gms.common.api.ApiException: 10: , null, null)

Steps taken:

1. Added necessary information for OAuth consent screen --

2. Added package name and SHA1 fingerprint in the google cloud console for my app:

• Got the SHA1 fingerprint (running gradlew signingReport command)

• Added it with package name

--

3. Implemented the code:

• AndroidManifest.xml (internet permissions are there) This client Id is there in strings.xml

• in app/build.gradle

       signingConfigs {
           debug {
               keyAlias 'androiddebugkey'
               keyPassword '*****'
               storeFile file('mykey.jks')
               storePassword '*****'
           }
       }
  
       buildTypes {
           debug {
               signingConfig signingConfigs.debug
           }
       }
  

  dependencies {
          implementation 'com.google.android.gms:play-services-auth:20.7.0'
      }
  

• in android/build.gradle

  allprojects {
      repositories {
          google()
          mavenCentral()
      }
      buildscript {
          dependencies {
              classpath 'com.google.gms:google-services:4.3.10'
          }
      }
  }
  

• Flutter login.dart

  class LoginAPI {
    static final _googleSignIn = GoogleSignIn();
    static Future<GoogleSignInAccount?> login() => _googleSignIn.signIn();
    static Future signOut = _googleSignIn.signOut();
  }
  
  onPressed: () async {
      var user = await LoginAPI.login();
      print('user.....');
      print(user);
  },
  

What am I doing wrong? Are there any more steps I'm missing.

NOTE: I'm implementing Google sign in without Firebase, as we also have a api to handle login. So google-services.json has not been added.

Any solutions from this post: https://stackoverflow.com/questions/54557479/flutter-and-google-sign-in-plugin-platformexceptionsign-in-failed-com-google did not help with the current issue for the same reason. Any other steps not involving firebase, and relevant to current implementation were already taken.

Found the issue with this- It was because of the incorrect key SHA-1 key. For people implementing google sign-in without firebase:

1. First, run flutter doctor command: flutter doctor -v

It will return the java bin library path: Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java

2. Create you jks file: keytool -genkey -v -keystore '<path\wher\you\want\to\create\it\file_name.jks> -storetype JKS -keyalg RSA -keysize 2048 -validity 10000 -alias 'your_alias'

Add details as requested, once the file is created - go to that path.

Move the file to your projects 'android/app/' folder

3. Run this command in android studio keytool -list -v -keystore <path\to\your\jks\file>

Enter you password:

Copy the SHA-1 key returned (We will be using this key)

4. Add this sha fingerprint to you google cloud console.

Google sign-in should work as expected.