How to generate unsigned APK for testing in React Native (Ejected Expo App)

I am trying to follow the instructions here:

https://icetutor.com/question/build-and-install-unsigned-apk-on-device-without-the-development-server/

In order to generate a unsigned APK with React Native.In the post it says to use the following command:

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

I can't seem to find the right folder to execute this command.In my project folder, I don't even have index.js what I have is App.js. This was not my choice, when I intitialised the Expo App (before I ejected it, Expo's template already gave me the App.js so I went with it).

Do I just change the index.js to App.js above?or where should I execute that command?

Is that the right instructions on how to generate a unsigned APK in React Native?How does one generate a unsigned APK in react native?