how to test back end post request with jest and supertest ?

FrontEnd

fetch("http://localhost:8081/test", {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ url }),
    })
      .then((res) => res.json())
      .then((result) => console.log(result)
});

BackEnd

app.post("/test", async (req, res) => {
  const url = req.body.url;
  const fullUrl = `https://api.meaningcloud.com/sentiment-2.1?key=${API_KEY}&url=${url}&lang=en`;
  const response = await fetch(fullUrl);
  const data = await response.json();
  res.send(data);
});