Here's how you can enable a success message on the cart page:
1. Select an offer to edit on the Offers page
2. Scroll down to find the 'Success Message' field. Add a message there as per your preferences and use variables to personalize it to your shopper. Click the Save button.
3. You also may have to adjust the cart page messaging options from the Storefront to find the right selector and how the cart change is detected to match your theme.
If you face any trouble enabling the success message, please reach out to us.