If you are an active Gold Member or have an active Gold Trail and you are not able to design then, it is because you have the iPhone version of the app on your iPad. 

The app titled DSDApp by Coachman (red icon) is meant for iPad versions. 

Link: https://apps.apple.com/us/app/dsdapp-by-coachman/id1470224189

The app titled DSDApp by Dr. Coachman (white icon) is meant for the iPhone versions.