PaymentExpress: Error : 0 Authentication Error

-- HikaShop version -- : 3.2.2
-- Joomla version -- : 3.8.5
-- PHP version -- : 7.1
-- Error-message(debug-mod must be tuned on) -- : Error : 0
Authentication Error Authentication Error

I have installed and used PaymentExpress many times. In fact, I was the one who got you to do the plugin.
So, this is odd.

It is all set up correctly and the credit card info is correct.

When you hit FINISH on the shopping cart it then throws this error and sends you back to the first Cart screen.

Now, I seem to remember that there was or should be a pxpay.php file that was created in the site root.
There isn't any such file there.

Aha!
So PaymentExpress and PXPAY are now separate plugins!
That would be why...

QUESTION:
Is the HikaShop PaymentExpress plug-in actually PaymentExpress PXFusion?

It is acting like PXFusion but the credentials (USerID and KEY) I have for PXFusion are not working.
Same Error 0.