AuthorizeNet Relay Response Module Documentation.
Your AuthorizeNet configuration applies to
all AuthorizeNet payment options in your store configuration. To make a payment
option AuthorizeNet enabled you will need to select one of the cards compatible with
AuthorizeNet in the OPTION TYPE drop down menu as seen below. By doing this, any
transaction where the shopper selects an AuthorizeNet option will be automatically
processed live through your AuthorizeNet Account. If you do not have an AuthorizeNet
account TNL Total Solutions can
provide one.

Figure 1
You are provided with 2 configuration options for all of your AuthorizeNet payment
types. If you have multiple payment types that utilize AuthorizeNet you only need to
configure one of the payment options for use with AuthorizeNet and the configuration will
be maintained for AuthorizeNet payment options..
Your two options are simply your AuthorizeNet ID which is assigned to you when you create
your AuthorizeNet account and the AuthorizeNet URL that TechCart will post the transaction
into. This url is usually: https://secure.authorize.net/gateway/transact.ddl
check with your AuthorizeNet representative to be certain.

Figure 2
AuthorizeNet Account Configuration
Once you have added these settings to TechCart you are ready
to configure the AuthorizeNet side of things. Configuring your AuthorizeNet Account
isn't as daunting as it will appear at first. Here are 5 simple steps:
Step 1:
Login to the AuthorizeNet Site using your merchant ID and password. This
information was provided to you when you created your AuthorizeNet account.
Step 2:
From the main merchant menu select settings
Step 3:
From the settings menu select MANAGE URLs
Step 4:
You will want to add a url to this screen with the following settings:

AuthorizeNet Add URL Screenshot
This url should be the non-secure url to CART.CGI. You will want to check the items as shown in the diagram above. They are:
Add To List Of Valid Referrers
Add To List Of Valid ADC/ / Receipt Link URLs
ADC Relay Response Default URL
Step 5:
Add The Final URL:
Next, Add The second url should point to the secure URL of
CART.CGI. You will want to set up the url with the following settings:

AuthorizeNet Add Url Screenshot #2
You will want to check the items as shown in the diagram above. They are:
Add To List Of Valid Referrers
Add To List Of Valid ADC/ / Receipt Link URLs
Receipt Link Default URL
Finally you will want to test your setup with a
few test orders. Leave Your AuthorizeNet account in Test Mode for these
transactions. Once you are satisfied that all is in order you are ready to take your
AuthorizeNet account out of test mode and go live.