Thanks for getting back to me. I couldn’t find anything in the error log. I reinstalled the plugin and made a new button, however, the URL provided doesn’t work in PayPal apparently, a message comes up saying
“We’re sorry. That URL won’t work. Please enter an “https” URL.”
I changed “http” to “https” and the IPN’s in the history log on PayPal now say “Sent” yet none of them appear in the IPN section in the wordpress admin panel.