How can I use form caculator twice on my PayPal form

how can I use form caculator twice on my form and
depending on the responses, get both to appear in my Paypal payment box?

You may setup the conditions to calculate based on the options selected. The calculated result can be sent to the PayPal payment using the final result.

Please refer to the following guides that can help you with achieving your requirement.

https://www.jotform.com/help/268-Conditional-Logic-Inserts-Text-Calculation-Into-A-Field

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

Hope this information helps!