You have to build apk again to see changes.

You can't do it. You must publish a new version. And you cannot delete any version from Google play console

The command that you have used ./gradlew clean ./gradlew assembleRelease npx react-native run-android --variant=release simply creates a new AAB (here you can check the difference between an APK and an AAB) for release on the Google Play Store.

From your question:

but i found apk first one not update one.

It seems that the new AAB is overwriting the previous one (which is expected). So, if you want to release this new version, you must go to your Google Play Developer Console, create a new version for production, and upload the AAB you just created.