How do I add the paypal payment option? I am using the Pro version

Hey! Thanks for the question!

Let me give you the link to user guide section, where you can find out about payment options, and particularly, PayPal settings:
goo.gl/f0GsEh

Go to Ecommerce WD Options, navigate to Checkout tab, where you will see these settings. Let me know in case you will have further questions.

Thank you! Have a great day!