Paypal: How to allow users to pay directly from form instead of redirecting to PayPal checkout page?

Thanks for the help, Sven. I wasn't aware of how to use those widgets. 

Can you help me with one more thing? I'd like to have a second page to this form where my customer pays via PayPal. I'd like them to put in their name, address, and credit card info and click a button to pay directly from the form. If possible, I'd like the name, email, and address fields to auto-complete on future transactions.

Is this possible?

Both PayPal Pro and PayPal Express allow for paying via credit card directly in the form:

https://www.jotform.com/help/183-Difference-Between-PayPal-PayPal-Pro

Both require either a PayPal Pro or PayPal Business account. 

It would not be possible to have the data pre-populate based on previous submissions.

Would it or wouldn't it?

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

You can pass a calculation to the payment field but the payment is still processed in the same manner.  If you pass the total to a regular PayPal field, users would still be forwarded to PayPal for payment.