How do I change paypal due amount...

I have a form that, based on a specific field value, I want to change the PayPal amount.  I have 3 fields, only one is shown at a time, and if any of them has a specific value, I want to add $5 to the amount due.  When I try this with a text field, it works fine, but when I tried with the PayPal amount - it didn't update.

Thank you!

Hello,

I see that you are trying to add cost to the PayPal amount field directly. You can insert values into the payment field using payment settings Get Price Option. You can get values from a Form calculation widget to the payment's amount field.

On the other hand, when you use conditions to calculate, the field that contains the result may not be accessible by the payment field. The issue you are having is related to accessibility.

Hence first add a form calculation widget to your form:

After that, using conditions and other fields, define your calculation as you did on this form. 

After a successful calculation, you can pass that result to the payment field, using get price option:

Here I cloned your form and updated as I suggested. I am not sure this is what you want, but as I understand you want to add 5 to the calculation when one of the option values is DNP. Here is the form:

https://form.jotform.com/71133791623959

You can clone it and investigate it as you like, here is a guide on cloning:

https://www.jotform.com/help/42-How-to-Clone-an-Existing-Form-from-a-URL

At last, you can hide this calculation field and only show the payment field. This will make your form look better.

I hope this answer helps. Please don't hesitate to contact us for your further queries.

All the best!