Transaction Results screen too fast

After purchase is complete, I would like the results screen to remain for much longer than it does. Currently it only displays for about 1 second and then disappears.

Which page are you talking about ? The page on the payment gateway website ? I would need more information to help you as I don't know which page you're talking about.

After authorize.net purchase is successful (or unsuccessful), a results screen will show up that says either successful or credit card declined. It lasts for only 1 second, then a new page is loaded, so it is hard to read since it only lasts for about 1 second.

That must be because you set a URL in the "return URL" option of the authorize.net plugin.

Removing the URL there should remove the redirect at the end of the payment.

Alternatively, you can edit the file plugins/hikashoppayment/authorize_thankyou.php and remove/change the redirection javascript code to suits your needs.