How to send data through headers to restfull web serives

How to send data through headers to restfull web serives

how to send the data using header ,
i followed the below code but it is not working and not getting error in console also


                    type:'POST',
                    datatype:'json',
                    url:rootURL+"HashValue",
                    data:jsonData,
                    beforeSend: function(jqXHR) {
                    jqXHR.setRequestHeader("test", "test auth=" + token);
                        },
                    success:function(data,textStatus,jqXHR){
                        alert(data);
                       
                    },
                    error:function(jqXHR, exception){
}
please help to resolve the problemi

Thanks