Gateway address for Authorize.net (SIM)

I'm setting up my existing authorize.net account in the shipping module, and I don't see any place to put the gateway address (i.e. https://secure2.authorize.net/gateway/transact.dll). I'm probably missing something obvious, but I've looked through the options multiple times and don't see it anywhere.

See this posting where DrByte posted a link regarding the authorize.net gateway changes.

Why would you be attempting to enter Auth.net credentials into shipping modules.
The gateway address is already built into the SIM payment module but does need to be edited according to lat9's post.

RixStix:

Why would you be attempting to enter Auth.net credentials into shipping modules.
The gateway address is already built into the SIM payment module but does need to be edited according to lat9's post.

My current shopping cart software has a field for the gateway address in the shipping settings so I assumed ZenCart would too. I see it's handled differently here. Thank you.

Sorry for the curt sounding response. I didn't mean for it to sound so critical. That's what I get for being in a hurry.

No problem. I'm an admin in a Facebook group where we get asked the same answers over and over ad nauseam. I know exactly how it feels, lol.