Here at Spiro you now have the capability to change/add coupons to an existing order or after the invoice has been created

To do this, simply go to the order details section. You may scroll down to the bottom and see the section for managing live coupons. Swap out the current coupon for the desired coupon.

Here’s a sample:

Click on the coupon

Select which coupon you would like to apply

From there, it should show up like this:

Afterwards, hit save!

In the event that you haven’t created your coupon yet, I recommend checking this article to know more: Creating and Managing Coupons in Spiro