I am getting the error in my flutter project when implementing google sign in

Make sure your app migrated to androidx.(gradle.properties file contains line android.useAndroidX=true)

Also this error may be related to apk-file size (over 64K limit) on old Android devices (API < 21). Either change minSdkVersion to 21+, or configure your app for multidex.

In module-level build.gradle file add the multidex library as a dependency:

android {    defaultConfig {        ...        minSdkVersion 15         targetSdkVersion 29        multiDexEnabled true    }    ...}dependencies {  ...  implementation 'androidx.multidex:multidex:2.0.1'}

I don't know if you've resolved this, but here is how I fixed a similar issue.

1. Added the multidex dependency in the build.gradle(app) file of the android part.

    dependencies {     ...     implementation 'androidx.multidex:multidex:2.0.1' }

2. Also add this line of code in the same build.gradle file.

    defaultConfig {     ...     multiDexEnabled true }

3. Extend the FlutterApplication class and enable the MultiDex class there.

    class MyFlutterApp: FlutterApplication() {     override fun attachBaseContext(base: Context?) {         super.attachBaseContext(base)         MultiDex.install(this)     } }

4. Then add the class to your manifest.

    <application     android:name=".MyFlutterApp"     ... </application>

This should fix your issue.