Setting Up 2Checkout.com
The shopping cart in PhotoStore is already setup for 2Checkout.com. All you have to do is enter your account ID under settings in the management area.
Then in your 2checkout.com account click on "Setting up your site" on the welcome page after you login. Then click on "if you use a shopping cart please click here". Then about half way down click on "To receive these parameters, you must specify where they are sent.". Then set direct return to "Header Redirect" and the URL to the correct one below:
Photostore version 3.8.3 or less:
Photostore version 3.8.4 or greater:
(replacing YOUR_SITE_HERE with the URL to your site and PHOTOSTORE_INSTALL with the installation directory if it is in a directory other than the root.)