Setting up an app-exclusive discount in Shopify is a great way to incentivise your app users and boost their engagement. Here's a brief guide on how to do it:

1. Access the Shopify Admin: Log in to your Shopify account and navigate to the Shopify admin dashboard.

2. Go to Discounts: From the dashboard, click on "Discounts" in the left-hand sidebar menu.

3. Create a New Discount: On the Discounts page, click the green "Create discount" button in the right-hand corner.

4. Choose Discount Type: A popup will appear, select the type of discount you want to offer. Choose from the following: Amount of products, amount off order, by Y get X, or shipping discount.

5. Choose Discount Method: To ensure it's app exclusive, choose "code" under "method" instead of an automatic discount.

This is because Shopify does not yet give all sales channels the ability to create channel-exclusive automatic discounts. This way, you can send the discount code via push notifications and display it within the App.

6. Input the Code: Under the "Code" section, input a custom code to align with your app's branding or use a generic code like "APP15" for simplicity.

7. Set Discount Details: Enter the discount value, whether it's a percentage or fixed amount, in the appropriate field.

8. Define Discount Requirements: Scroll down to the "Customer Eligibility" and "Minimum Requirements" sections. Here, you can set conditions that make the discount eligiable to specific customer segments and set a minimum spend.

9. Set Discount Usage Limits & Combinations: If desired, you can set usage limits for the discount and allow it to be combined with other discounts. For example, you can limit the discount to one per customer or specify a maximum number of times the discount can be used overall or allow the discount to be combined with Shipping discounts.

10. Set the date Active Date: Here you can schedule your discount to go live to your customers. Select the appropriate time and date.

11. Save and Promote: Once you've set up all the necessary details, click on the green "Save" button in the top right-hand corner to create your app-exclusive discount. Now, it's time to promote it to your app users through push notifications, in-app messaging, or app-specific marketing campaigns.

Remember, the exact steps and options may vary slightly depending on the version of Shopify you're using or any installed apps. If you encounter any difficulties or need more specific guidance, don't hesitate to reach out to us for more assistance.