You Are Right!
That fixed it! Thank you again for time and patience, Ray!
I will post one last update tonight for others to follow just in case it helps.
Have a great day!
Errors made in connecting with Authorize.net:
1. Not setting the Name and Description fields when inserting the ADD TO CART button.
Drop error codes in checkout_failure.php. Refer to direction in previous posts within this thread.
1. Create two pages:to insert an Add to Cart button page (example: donation.php) and another to add a checkout button.
2. On the add to cart page: insert Add to Cart button. I set ID field set to 1 and Replace if in Cart set to Replace; Quantity field set to 1 and hidden; Price field set to updatable via list. Where I made a mistake was in not setting defaults for the Name and Description fields. I set these to Name: Donation. Description: Thank you for your Donation to . . .
3. On the Checkout button page: Insert a Form via the Form Manager (eCart tab). Configure as desired. Then, outside of the Form, place a Checkout button. Run the Checkout Wizard and configure as desired.
4. Go to each page generated by the Checkout Wizard (four in total) and remove the thumbnail for an image.
5. Upload and test.
6. If not successful, drop the error codes from the Bindings panel onto checkout_failure.php. The most useful being: Reason Code, Reason Text, and Full Request. When you apply Full Request, be careful. It will return your Login ID and your Transaction Key, so be sure to remove the error codes immediately after testing.
If you have a more specific question about the process, I would be glad to share what I have learned.
Many thanks to Ray for the help in solving this problem.