1cd android
2./gradlew assembleRelease

1 cd android && ./gradlew assembleRelease

1 react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res/

1...
2android {
3    ...
4    defaultConfig { ... }
5    signingConfigs {
6        release {
7            if (project.hasProperty('MYAPP_RELEASE_STORE_FILE')) {
8                storeFile file(MYAPP_RELEASE_STORE_FILE)
9                storePassword MYAPP_RELEASE_STORE_PASSWORD
10                keyAlias MYAPP_RELEASE_KEY_ALIAS
11                keyPassword MYAPP_RELEASE_KEY_PASSWORD
12            }
13        }
14    }
15    buildTypes {
16        release {
17            ...
18            signingConfig signingConfigs.release
19        }
20    }
21}
22...

1$ keytool -genkey -v -keystore my-release-key.keystore -alias my-key-alias -keyalg RSA -keysize 2048 -validity 10000