Insecure Connection - "Your connection is not secure"

I am trying to visit the Wiley CPA website but I get the error message saying "Your connection is not secure". So I tried to look into the certificate by typing in the location field of the window type or paste the URL of the website with the https:// protocol prefix (https://wileycpa.com). However, I just wanted to bypass the error message but I forgot to delete the https:// protocol prefix, and then when I clicked on the add exception, it now just completely messed it up, because of having the https:// protocol prefix before the websites address and now I get this message. Could someone please help me with this problem I would greatly appreciated it, Thank You.