You can configure HTTP Request Headers optionally. HTTP Request Headers define the operating parameters of an HTTP transaction. The Specify HTTP Request Headers option allows you to add one or more HTTP Request Headers as Name:Value pairs. The Name field provides a list of http headers as a drop-down menu, but also allows you to type in a valid parameter. Depending on the selected parameter, the Value field provides a list of appropriate values as a drop-down menu or you can type in a proper value.

Click the + button and fill in the required Name and Value.