From the error message you're getting, and if you're using a mobile device to purchase Love, I can advise you to restore your In-app Purchases. This can be done by following these instructions:
1. Navigate to the correct page by tapping "Fandom" in the lower menu and hitting the "Profile" icon in the upper-right corner.
2. Access the "Edit Profile" menu by hitting the "Pencil" icon.
3. Scroll down until you reach the "Manage Purchases" menu option.
4. Tap the "Restore In-App Purchases" button to attempt this fix.