Android update existed apk

I've increased the version code and name in manifest file and exported the apk. Then here is what i've done :

play.google.com -> click my apk -> APK -> Beta Test -> upload new apk and expansion file (.obb file) -> click 'temporary storage' button (i don't know the reason why there isn't 'released on beta' button) -> access to test URL -> playstore -> click 'update' button -> app already exist

I don't know what's wrong with it. Has anyone run into the same error?