JSFiddle - React, Tailwind, and code Playground

JavaScript

var alphabet = new    Array("a","b","c","d","e","f","g","h","i","j","k","l","m",
                             "n","o","p","q","r","s","t","u","v","w","x","y","z");


var original = "cat";
var encrypted = "";
for (var i=0; i<original.length; i++ ) {
    var item1 = alphabet[Math.floor(Math.random()*alphabet.length)];
    var item2 = alphabet[Math.floor(Math.random()*alphabet.length)];
    encrypted += original[i] + item1 + item2;
 
    
}

   alert(encrypted);