This is the simplest authorization for a request. With basic authentication, you need to input your credentials to authenticate the request. These credentials will be encoded into the Authorization request headers. Do as follows:
In the Authorization tab of a web service request, set the Type as Basic.
Pass in your username and password to authenticate the request, then click on Update to HTTP Header. The username and password are encoded to the Authorization request of the HTTP Header tab, as you can see below.