eChecks are available in the checkout when used with either the Authorize.net or eProcessingNetwork Payment Gateways.
The eCheck option must be enabled in the payment gateway account setup as well as the cart.
In the AspDotNetStorefront admin console, go to Configuration > Site Setup Wizard and check the box next to E-Checks through supported gateway in the Credit Cards & Other Payment Methods section, then click Save.
Go to Configuration > Settings and search for the StoreCCInDB setting. Set the value to Yes.
It will then be shown in the Payment Info page as one of the payment methods:
Once the required information is filled in, it will be processed similar to a Credit Card transaction. Note that Ad-Hoc Charge/Refund is not available on eCheck orders.