Dose the PrePopulate App work for paypal price?

Dose the PrePopulate App work for paypal price? I try it, but it dosn't work.

That is right. The payment field is not available when using Prepopulate field App.

This is by design for security purposes.

The option you can try is to populate the field instead via the URL parameter value method.

Example: https://www.jotform.co/form/72277047907867?myProducts[price]=20.00