DDC does not use iCloud for any work application.You must be using your own icloud account.

You have two choices:

  • You can purchase more iCloud storage as the email suggest. (I have my daughter & my wife on my iCloud account so i purchased the 50 Gigs for $0.99 a month.)
  • Or you can reduce what you are keeping in your iCloud storage. To do to that, Go to Settings, Tap on Your Name, then tap on iCloud, then Manage storage. From this screen you can see what apps are using the most storage. if it is Photos, you can go and delete some of your photos to free up some space. You can also turn apps off from using storage too. 
I hope this helps