Fetch values from Json String inside Ajax function

Question

Here is my Json String

{"log_from":"web","type":"activity"}

I am trying to display values on my DataTables with Ajax Request

'columns': [
      
        { className: 'ldar-Trcontrol', data: 'properties' , name: 'properties' },
   ]

properties contain my json String and the sting is displaying on my datatable. But here I need to fetch the value for "type" and "log_form" seperately