JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="hora" />

JavaScript

document.getElementById('hora').addEventListener('keyup', function(e){
    var str = this.value.split(':').join('');
    if (str.length > 6) str = str.slice(0, 6);
    var formatado = str.match(/.{1,2}/g).join(':');
    this.value = formatado;
});