Signing APK file in flutter

1 . Create key.properties inside android/key.properties file with the following contents

storePassword=xxxxxxxx
keyPassword=xxxxxxxx
keyAlias=alias-name
storeFile=C:/path/to/.keystore


2. Add the following codes inside android/app/build.gradle file

def keystoreProperties = new Properties()
   def keystorePropertiesFile = rootProject.file('key.properties')
   if (keystorePropertiesFile.exists()) {
       keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
   }

3. Add the following codes inside android/app/build.gradle file's just after default config

    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.debug
            signingConfig signingConfigs.release
        }
    }


4. After these build aab file using the following command
flutter build appbundle --release --obfuscate --split-debug-info=/debug_info

5. Then read on another article of how to upload aab file to the store