1. First login to your Authorize.net account 
  2. Click the “Account” link at the top. 
  3. Click on the link on this page that looks something like:  “API Login ID and Transaction Key”   Click the generate button(s) if needed. 
  4. Use these as login information under Merchant Account settings in Net Community. Authorize.net API Login ID should be entered in the Gateway ID field, and the Transaction Key should be entered in the Password field for the merchant account in NetCommunity.
  5. Click Save for the changes to the merchant account.