If Concepts is downloaded or updated while signed in to a different App Store account than used to make the in-app purchase, then Apple will not provide a digital receipt for your purchase. Without that digital receipt, we cannot recognize your purchase. Unfortunately to solve this, you will need to delete Concepts from your device and reinstall while signed in to the correct account. But FIRST, you must backup your drawings.

Here's how to backup your drawings:

1. Open the iOS Files app
2. Go to On My iPad
3. Create a new folder called Concepts Backup
4. Open the Concepts folder
5. Tap Select in the top right corner
6. Tap every folder in the Concepts folder to select it
7. Tap Copy in the bottom bar
8. Navigate to the new Concepts Backup folder you created
9. Tap Copy

Once you have verified all your drawings are backed up, you can delete Concepts and reinstall while signed in to the correct account. After running Concepts verify that your purchases have restored. Once you have done that you can move the drawings you backed up back into the Concepts folder.