YALP and Aurora get the APK directly from the play store, that is the whole point about these programs. Get the source to Aurora (or YALP) and find out how it

YALP and Aurora get the APK directly from the play store, that is the whole point about these programs. Get the source to Aurora (or YALP) and find out how it downloads the APK from the play store. Now either build something which does what you want (e.g. feed it an identifier and it downloads an APK), simplify the existing code until only the required functionality is left or use Aurora as it is. You can feed it a Google account (if you have one) to log in to the play store or it can do so 'anonymously'.