JSFiddle - React, Tailwind, and code Playground

HTML

<body>
</body>

JavaScript

var overlay;
condition = "test2";

testCondition = function(callback) {

  if(condition == "test") {
    overlay = $("<div></div>");
  }
  else if (condition == "test2") {
    console.log("first-log");
    overlay = $("<span></span>");
  }

  callback(overlay);

}

testCondition(function(callback){
   overlay.prependTo("body");
});