Answers for "generate build in react native"

react-native release build

cd android && ./gradlew assembleRelease

react native build

cd android
./gradlew bundleRelease

export app react native

mkdir -p android/app/src/main/assets
react-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
cd android && ./gradlew assembleRelease -x bundleReleaseJsAndAssets

- Your APK will be present in the folder
<project>/android/app/build/outputs/apk/release

how to make apk in android studio reac native

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