Getting custom Paypal amount from calculated value

Hey support,

In most of my forms I calculate my payment amounts into a hidden field, then tell the Paypal widget to pull the custom amount from that hidden field. Looks like this during Paypal integration:

Here's the problem. The "Get amount from" option doesn't always show up for me, and I can't figure out why. Here's what I see sometimes when I try to do my regular Paypal integration (whether the donation box is checked or not):

Any hints? Thanks in advance!

Hi,

If there is no calculation field in the form, there will not be a field to get the value from.  The option will not be displayed.

http://www.jotform.com/help/275-How-to-pass-a-calculation-to-a-payment-field

Here it is without a calculation widget in the form:

And here it is with one:

If you have any further questions, let us know and we will be happy to help.

Follow-up question here:

I now have a form with a calculation field that will not tell my PayPal widget the amount to charge. Here's one of the calculations:

Here's what I see when I try to link my calculation field to my widget:

Any tips? Thanks in advance for your help!

The value needs to be captured from a calculation widget:

https://www.jotform.com/help/259-How-to-Perform-Calculation-in-the-Form

It is not possible to pass a conditionally updated or calculated value.  An actual calculation widget needs to be used.