JSFiddle - React, Tailwind, and code Playground

JavaScript

function parseQueryString(qs) {
    var urlParams = {};
    var e,
        a = /\+/g,  // Regex for replacing addition symbol with a space
        r = /([^&=]+)=?([^&]*)/g,
        d = function (s) { return decodeURIComponent(s.replace(a, " ")); },
        q = qs.substring(1);

    while (e = r.exec(q))
       urlParams[d(e[1])] = d(e[2]);
    return urlParams;
}

console.log(parseQueryString("CODRET=1&MSGRET=JA CONFIRMADA"));