Answer 1

Add an APK

-Go to your Google Play Developer Console.(https://play.google.com/apps/publish/)

-Select All applications All applications > Add new application.
-Using the drop down menu, select a default language and add a title for your app. Type the name of your app as you want it to appear in Google Play.
-Select Upload APK.
-Choose from the Production, Beta, or Alpha channels and select Upload your APK. For more information on alpha/beta testing, go to use alpha/beta testing & staged rollouts.
(https://support.google.com/googleplay/android-developer/answer/3131213)

Hope this helps.