1. Click Settings on the Navigation bar and select Payments & Taxes from the drop down
2. Click on Add New Payment Type
3. Fill the details and click on Add
Name : Friendly Display Name like "CardFlight"
Payment Type : Select Card (CardFligth USA)
Status : Select Enabled or Disabled option whether you want the payment type to be active or not
4. At this point, you need to enter the API Key and Account Key which will be provided by us after you order the Card reader
Click Save to complete adding the Payment Type
5. After adding the payment type, it must be assigned to the Store. Refer the following article to know How to assign a Payment Type to the Store?