Need help with custom amount for Stripe payment in Breezing Form

I am creating a payment form using Breezing Form Pro in Joomla. It will collect payment from my clients using Stripe Connection. I have run into an issue where the backend of the form requires a set Payment Amount for the Stripe payment. I need to be able to let the customer type a custom Payment Amount into a textfield since each customer will have a different account balance. I don't know how to make that work.