1cd android
2./gradlew assembleRelease

1npx react-native run-android --variant=release

1Before uploading the release build to the Play Store, 
2make sure you test it thoroughly. 
3
4mkdir -p android/app/src/main/assets
5react-native bundle --platform android --dev false --entry-file index.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res
6react-native run-android --variant=release
7
8Export Apk -
9cd android && ./gradlew bundleRelease -x bundleReleaseJsAndAssets
10
11- Your AAB BUNDLE will be present in the folder
12<project>/android/app/build/outputs/bundle/release

1For Windows 'cd android' and then run gradlew assembleRelease command , and find your signed apk under android/app/build/outputs/apk/app-release.apk

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