Watched the video, read the posts & reviewed this link: http://rsvpmaker.com/2010/11/how-to-set-up-paypal-with-rsvpmaker/ I Used the paypal_constants.php with my API configs as test & even temporarily put that php file in my root website dir, still says error: file not found. The 18.104.22.168 update said the system default is in /var/chroot/home/content/11/8851211/html (when using that path, system says OK.)
I must be doing something wrong. When logging into Filezilla, I have my host at the root/my_domain/wordpress,wp-admin,wp-content,wp-includes,etc/
Didn't want to leave it default. Thanks, sorry for being confused!