To buy content from the application I use the guide
When calling the onIabPurchaseFinished() method of onIabPurchaseFinished() following message is IabHelper.OnIabPurchaseFinishedListener :
"You must be logged in to your Google Account"
A developer account is running on the device (which was added to the developers in the google console).
Created apk and uploaded it to alpha version on GooglePlay . What could be the problem?