A Digital Developer needs to add a new form to the shopping cart page to allow customers to enter their rewards pass ID. There is already an existing Cart.js controller that handles processing of the other cart forms.
In addition, a formfield node is in the form XML and the necessary form input is present in the ISML template.
The code below is the submit button for the ISML markup.

What additional steps must occur before the Digital Developer can begin writing the processing code forthis request?