Coupon field on 'Update Payment' hosted page

Coupon field on 'Update Payment' hosted page

HI All,

How can we add a coupon field to the 'payment update page'.

We want customers to be able to input a coupon code when they update their credit card details. I have created a coupon and associated it with the main plan we have but cannot find the setting to add it to the ‘Payment update page’ hosted form.

Thanks

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