cartercar on "[Plugin: Seamless Donations] Not processing Credit Card..."

Hello,
I am just trying to setup this plugin and have had some success but not complete. I am able to make a donation through Paypal when I also sign in to paypal. I can't, however, make a donation when I try to use a credit card while NOT being signed in to Paypal as some of our donors but need to do. Is there something I am missing in the setup or is there possibly something wrong on the PayPal side that I need to do to allow for this type of donation?
Thank you for your help and for this plugin. It seems nicer than others I've been looking at.
Carole

https://wordpress.org/plugins/seamless-donations/