How can I test android app with leaderboard before publishing it in Google Play?

I would like to test my android app with a leaderboard before I publish it in Google Play.

I have created a simple game and a leaderboard in Google Play Console.

I have created the android app by Android Studio and generated a signed bundle and uploaded to Google Play Console (signed by Google). I created a release for Closed tracks and released to Alpha. Clicked into 'App releases' => 'Alpha' 'Manage' => 'Manage testers' 'Closed Alpha Testing', I saw 'Opt-in URL' = 'An opt-in link will be available here when you publish your app.' There was not URL for me.

But I want to test it before I publish it, can I? Many thanks.