JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <textarea placeholder="Text to echo" class="fake_form"></textarea>
  <button class="form_submit">submit </button>
  <button class="form_reset">reset</button>
  <textarea placeholder="Echoing result" class="res"></textarea>
</body>

JavaScript

const fake_form = document.getElementsByClassName("fake_form")[0];
const res = document.getElementsByClassName("res")[0];
const submitHandler = () => {
  fetch("https://cors-anywhere.herokuapp.com/https://postman-echo.com/post", {
    "method": "post",
    "data": fake_form.value
  }).then(r => r.text()).then(t => res.value = t);
}
const resetHandler = () => res.value = "";
const form_events = [{
  "type": "submit",
  "handler": submitHandler
}, {
  "type": "reset",
  "handler": resetHandler
}];

form_events.forEach(({
  type,
  handler
}) => document.getElementsByClassName(`form_${type}`)[0].addEventListener("click", handler));