How is the PayPal gateway set for Protected Content

The Payment section of the Protect Content plugin and on the last line of the Dialogue, the PayPal Butoon or URL is requested and I'm unclear on what is asked for . Do I create a buynow button on a different page and link to it? that can't be it. Tks in advance for your assistance

Maybe I create a button copy the code generated by paypal and paste the code in the line asking for the Button?