On Payment Plugins management screen, click on os_authnet payment plugin to edit it. The following parameters need to be configured:

  1. Mode: Set to Test Mode if you are testing the system and set it to Live Mode when you go live.
  2. API Login
  3. Transaction Key

Sometime, your might not work well in Test Mode. But it does works in Live Mode. In that case, if you want to test it in test mode, you can use the following account for testing purpose:

  1. API Login: 2Sht9m67PD
  2. Transaction Key: 35J2rq5d6LtJ2Yg6