While in Fallback, the customer profile is not available, and you cannot create new customers, or edit customer information. However, you can use the Assign Customer link in the cart to assign a customer to an order in Fallback. Assigning a customer to an order is not required.
To assign a customer to an order in Fallback:
Click or touch the Assign Customer link.
Enter a customer identifier in the popup dialog window.
The customer identifier can be an email address or a customer ID. You must enter at least one identifier to assign a customer to an order in Fallback. Entering the or the customer’s first or last name is optional.
Touch or click Save.