I am trying to upload my app to Google Play using the developer console. As of a week or so ago they have made it so that each app has a unique key string. You have to use t
On the new google play console its quite simple.
After uploading your apk it will appear under the upload section as such:
Off to your right you should see the classic three dots which will bring up this window:
Click on "Upload expansion file (.obb)" and there you go