Can't launch the App from Google Assistant in Android

Question

I was trying to launch my application from Google Assistant. They say that we need to publish our application and nothing else is required.

Reference: https://developer.android.com/guide/app-actions/overview#app_actions

So, I have published my application for internal testing to verify this. After downloading that application from Play Store link, I tried launching the application but that isn't working. Does publishing it for internal testing doesn't work?