JSFiddle - React, Tailwind, and code Playground

JavaScript

var result = {
   "d":
   "[
        {
            \"Column1\":\"PA\",
            \"Column2\":\"XAL2Y2\",
            \"Column3\":\"BLK\",
            \"Column4\":\"2019\"
        }
    ]"
};

console.log(JSON.parse(result.d))