Yes, as an artist with an active contract. When you create a release, you'll find the section "Or choose a cover from the Cover Generator" in step 1 "Upload", below the field for the cover image. There you'll see your saved covers. Click on the cover you want, then click "Continue" or "Save". The release will use the cover at a size of 3000 × 3000 pixels.
You can still upload your own image as well. If you've chosen both, the uploaded image will be used.
If you later delete a cover in the Cover Generator, it won't affect your release, because the release keeps its own copy.