How to do authorize.net module

[Guest]

I'm hoping someone can advise on what I need to get authorize.net working. I have a test account they provided me but I'm getting:

 

(13) The merchant login ID or password is invalid or the account is inactive.

 

everytime I try. I'm wondering do I need to use what is in the contributions section? Should it work right without this?

 

I would appreciate anything that could walk me through the proper configuration for this module.

 

Thanks,

Tim Jordan