Answers for "create release apk file react native"

react native build apk

'
For apk : cd android && ./gradlew assembleRelease
For aab : cd android && ./gradlew bundleRelease
,

react native release apk command

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

react native create apk

Place your terminal directory to android using:

cd android
)================
For Windows, 
  gradlew assembleRelease
)=================

)=================
For Linux and Mac OSX:

./gradlew assembleRelease
)==================

build apk from react native

React Version 0.62.1
In your root project directory

Make sure you have already directory => android/app/src/main/assets/, 
if not create directory, after that 
create new file and save as index.android.bundle 
and put your file like this android/app/src/main/assets/index.android.bundle

///////////////////////
// building bundles //
//////////////////////
npx 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/

///////////////////////
// building Debug Apk //
//////////////////////
cd android && ./gradlew assembleDebug

///////////////////////
/////Get the Apk/////
//////////////////////
cd app/build/outputs/apk/
  
  

///////////////////////
// building Release Apk //
//////////////////////
cd android && ./gradlew assembleRelease