how can I accept a Paypal payments?

You can use our Paypal payment integration: https://www.jotform.com/help/165-Setting-Up-Your-First-Order-Form

Also, you might like to enable IPN (Instant Payment Notification): https://www.jotform.com/help/276-How-to-Enable-IPN-for-Paypal

I you have another question, please open a new thread, we will be glad to assist you.