Flutter Android App Signing

 1- Generate and get .jks from android studio.

2- Create a key.properties under android file as following format.

storePassword=
keyPassword=
keyAlias=
storeFile= //file path of jks

3- Go to your app level build gradle and get key.properties with following code.

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

4- Add signing configurations inside the android tag.

signingConfigs {
           release {
                keyAlias keystoreProperties['keyAlias']
                keyPassword keystoreProperties['keyPassword']
                storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
                storePassword keystoreProperties['storePassword']
           }
      }

5- Make sure about your signingConfig is release as following ;

buildTypes {
          release {
              signingConfig signingConfigs.release
          }
      }

6- Run ‘flutter build appbundle’ command .