fetch('/api/v1/auth', {
			method: 'POST',
			headers: {
				'cache-control': 'no-cache',
				'content-type': 'application/x-www-form-urlencoded',
			},
			body: {
				username: "user",
				password: "pass"
			}
		})

var data = "username=test123&password=test123";

var xhr = new XMLHttpRequest();

xhr.open("POST", "/api/v1/auth");
xhr.setRequestHeader("cache-control", "no-cache");
xhr.setRequestHeader("content-type", "application/x-www-form-urlencoded");

xhr.send(data);

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === 4) {
    console.log(this.responseText);
  }
});