How to remove the credit card info from a shopping cart when a promo code gives a 100% discount

We’ve heard about special code we can put into the shopping cart so that when a user enters a 100% off promo code the credit card fields either disappear or are no longer mandatory.

Does anyone have any insight into this?

Thank you!

I was in help chat recently regarding this same issue. As of now, Keap has no way of removing the need for CC numbers to be filled in, despite the promo codes. I find it leaves my customers with a feeling of distrust, like, is this really free, will they secretly charge me? I can’t believe so many other systems can figure this out but Keap cannot.