Allowing affiliates to choose their own discount code is a great way for affiliates to create a shopping experience on your store that resonates with their audience. This functionality exists on the program level, so you can have some affiliates who are able to choose their own code while still not allowing others to.
To enable this feature, head to the Programs tab in your dashboard and click on the program which you wish to enable this for.
From the program builder page, open the ATTRIBUTION & DISCOUNTS tab.
Next, scroll down to the Shorten Links section and toggle it on.
You need to either have Discount Codes or Both Links & Codes selected for this option to show.
Make sure to hit Save & Exit to save your changes.
Now, affiliates can choose their discount code when they join this program through a sign-up form, as well as change it within their affiliate dashboard.