JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="convert" placeholder="Insira os segundos">
<br>
<button id="converter">Converter</button>
<select id="optionsTime">
<option></option>
    <option id="minutes">Minutos</option>
    <option id="hours">Horas</option>
    <option id="teste">Teste</option>
</select>
<br>
<span id="resultTime"></span>

JavaScript

document.getElementById("converter").onclick = function() {
    timesquare(document.getElementById("optionsTime"));
};

function timesquare(s) {

var optionsTime = (s[s.selectedIndex].id);
var convert = document.getElementById('convert').value;

  if (convert < 60) {
    document.getElementById('resultTime').innerHTML = "Escolha um valor acima de 60";
    return;
  }

  switch(optionsTime){
    case "minutes":
        document.getElementById('resultTime').innerHTML = 'Vc escolheu minutos';
        break;
    case "hours":
        document.getElementById('resultTime').innerHTML = 'Vc escolheu Horas';
        break;

    default:
        document.getElementById('resultTime').innerHTML = "no result";
        break;
  } 
}