We need to remove the In App Purchase Product ID from the issue.
1. Go to the page: https://my.appstudio.net and select the issue
2. Click on edit Icon and remove the name of the issue and leave the box blank, If you are doing a free app leave this field blank.
3. Now unpublish and republish the issue after saving the changes.
Note:- On iPad you need to download the app before testing it again.