Request: formData() method

formData()

const formData = new FormData();
const fileField = document.querySelector('input[type="file"]');
formData.append("username", "abc123");
formData.append("avatar", fileField.files[0]);
const request = new Request("/myEndpoint", {
  method: "POST",
  body: formData,
});
request.formData().then((data) => {
  // do something with the formdata sent in the request
});