JSFiddle - React, Tailwind, and code Playground

JavaScript

// STANDARD WAY 
function step1(callback) {
    setTimeout(function()
    {
        console.log("Step 1 done After 3 seconds");
        callback()
    }, 3000);
}

function step2(callback) {
    setTimeout(function()
    {
        console.log("Step 2 done After 2 seconds");
        callback()
    }, 2000);
}

function step3(callback) {
    setTimeout(function()
    {
        console.log("Step 3 done After 1 seconds");
    }, 1000);
}

// CALLBACK HELL
function run() {
    step1(function() {
        step2(function() {
            step3();
        });
    });
}

run();