Hi Tammy,
If you need your API Login ID and Transaction Key for a test account, log into https://test.authorize.net and enter your Merchant Interface login ID and password. Then click Account from the main toolbar and Settings from the menu on the left. From here, select API Login ID and Transaction Key from the Security Settings section. Here you will see your API Login ID and can generate a new Transaction Key.
If you need this for a live account, the same instructions apply, but you'll need to log in at https://account.authorize.net.
Thanks,
Michelle
Developer Community Manager
