https://medium.com/flutterpub/flutter-andorid-keystore-path-on-different-os-d0fc30a24d4f

https://blog.csdn.net/joye123/article/details/94588949

signingConfig signingConfigs.release

Important is signingConfig signingConfigs.debug -> signingConfig signingConfigs.release

 signingConfigs {  
       release {  
           keyAlias keystoreProperties['keyAlias']  
           keyPassword keystoreProperties['keyPassword']  
           storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null  
           storePassword keystoreProperties['storePassword']  
       }  
    }  
    buildTypes {  
        release {  
            // TODO: Add your own signing config for the release build.  
            // Signing with the debug keys for now, so `flutter run --release` works.  
            signingConfig signingConfigs.release  
  
            minifyEnabled true  
            useProguard true  
        }  
    }  
}