You can move drawings from your local storage to iCloud Drive either from inside the Concepts app or by using the Files app.

Method 1: Inside Concepts

1. Open the Gallery.
2. Tap+Hold a drawing or folder under the On This iPad section.
3. Drag it over to the iCloud Drive location in the sidebar and release.

Method 2: Using the Files App

1. Open the Files app on your device.
2. Navigate to the path On my iPad > Concepts.
3. Select the drawings you want to move.
4. Move them to the path iCloud Drive > Concepts.

Walkthrough Series: iCloud Drive