Getting price from calculation

I am calculating a price trough my form and would like to autofill the payment field with this amount.

So I was setting as payment type "user defined amount" but the dropdown "Get price from" in the payment settings suggest me just "None (manual).

As I saw in your guide

https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field

there I should have the choice "calculation" which doesn't exist!

I also filled as second way try to set conditions which should fill the payment filed if there is choosen some product, but it doesn't work too.

You need to use the Form Calculation widget and not the Conditions. Here's a guide: How-to-Perform-Form-Calculation-Using-a-Widget.

If you have this widget, you can use it in the Payment field. The "total" field (label of the widget) will appear in the "Get Price From" drop down.

Please check this demo form: https://form.jotformpro.com/70696490195972

Here's how it should look like:

Hope that helps. If you have any questions, please let us know. Thank you.

Thank You, this was the solution.