document.addEventListener("DOMContentLoaded", () => {
  fetch("./test.txt")
    .then(function (response) {
      if (response.ok) {
        return response;
      } else {
        console.log(response);
      }
    })
    .then(response => response.text())
    .then(textData => {
      document.getElementById("one").innerText = textData;
    })
    .catch(function (error) {
      console.log(error);
    });
});