This illustration shows the Postman application with the GET method selected. The URL is http://hostname.domain:port/energy/1/api/usage/current/month/4859634. The GET method, the URL, and the Send button are bordered in red, and the Send button is active.

The Headers(1) tab is selected and contains a header key-pair. my-key appears in the key field and test appears in the value field.

The Headers(1) tab, and the header are bordered in red.