Once you have enable the coupon to feature on the pop-up, you can select the order in which the codes should appear on the pop-up.
Here's how to select the order:
Step -1: In your Voila dashboard, go to Manage Coupons and click on Select Order button.
Step - 2: You will see all the enabled coupons in the pop-up. Now, drag and drop the coupons in the order you want.
Then click on Save Coupon Order. This will save the order of the coupons.