Payment Gateway: Authorize.net
Authorize.net Account Configuration:
1) If you haven't already, you will need to establish a Authorize.net account.
2) Go to API Credentials & Keys page on your Authorize.net account via: Home >Settings > API Credentials & Keys to get the API Login ID.
3) On the same API Credentials & Keys page, You will see New Transaction Key option. Select this option and click on the Submit button and you will get your transaction key.
4) Insert the Authorize.net API Login ID, and Transaction Key values into this form.