You can select coupons of your choice to feature on the coupon pop-up which you can show on your cart page.
Here's how:
Step - 1: In your Voila dashboard, go to Manage Coupons
Step - 2: Enter the valid Coupon code (which you have already created in Shopify) in the field and click on “Add Coupon”
Step - 3: Enable the “Feature on pop-up” toggle button, add coupon description. You can also schedule the coupon and if needed add a terms and conditions link for the coupon.
Then click on Save button
Once you have enabled the coupons, you can also select the order in which they appear on the pop-up.