POST Request with Fetch API

fetch("https://...", {
  method: "POST",
  body: JSON.stringify({
    userId: 1,
    title: "...",
    completed: false
  }),
  headers: {
    "Content-type": "application/json; charset=UTF-8"
  }
})
  .then((response) => response.json())
  .then((json) => console.log(json));