为什么我的 POST 请求出现 404 错误？

Question

使用表单我将钱包信息添加到 JSON 服务器。当我逐步执行代码时，我可以看到我在调试器中输入的数据，但它以下面的错误结尾。我不知道为什么，如果它获取数据，我会收到 404“找不到文件”。我将钱包数据从 Json 服务器加载到页面，所以我新建了文件。

JSON:

{
  "purseData": [
    {
      "id": 1,
      "brand": "Jimmy Choo",
      "style": "Bucket",
      "color": "pink",
      "size": "Extra Large",
      "img": "https://media.jimmychoo.com/image/upload/q_auto:best,f_auto,dpr_2.0,w_900,h_900,c_fit/USPROD_PRODUCT/images/original/BONBONBUCKETSHUT_112562_FRONT_vg04.jpg",
      "desc": "undefined",
      "condition": "fair",
      "price": "500"
    },
    {
      "id": 2,
      "brand": "Coach",
      "style": "Lori Shoulder Bag",
      "color": "Brass/Canyon Multi",
      "size": "Medium",
      "img": "https://encrypted-tbn1.gstatic.com/shopping?q=tbn:ANd9GcRvWaKEder8QK6uE_vCxZUbnB9wYzTiC0SK335iHYBsFwY5GSObnQdL66UbTLKs2wXPssbpaxA6u7GiCBeAXS4ilqrl0LtoecOv9eNvpdNwPLFo5nlgqicS1WDio9oKeB0mQg&usqp=CAc",
      "desc": "undefined",
      "condition": "new",
      "price": "1000"
    },
    {
      "brand": "Celine",
      "style": "Ava Bag in Smooth Calfskin",
      "color": "Tan",
      "size": "Medium",
      "img": "https://encrypted-tbn2.gstatic.com/shopping?q=tbn:ANd9GcQXBzeij04RjU_VxK1_ousQyBlL9K32I5yl6dfyI4_ioxAmWEWGYVEb5VLaABL91r6nyWjq2Q_tLAsS71iY9bffma7dRRfp_zhvy0D9Bs80qvaQwBJiiRgGguJDLj_LmEA-vQ&usqp=CAc",
      "condition": "new",
      "price": 2300,
      "comments": "9 X 5 X 2 IN (23 X 13.5 X 6 CM),TRIOMPHE CANVAS, TRIMMINGS IN CALFSKIN,TEXTILE LINING,GOLD FINISHING,SHOULDER AND HAND CARRY,ZIPPED CLOSURE,ONE INNER FLAT POCKET,ADJUSTABLE STRAP WITH A MINIMUM DROP 8 IN (22 CM) AND MAXIMUM DROP 9 IN (23 CM),REFERENCE : 193952BZJ.04LU",
      "seller": "Guy George",
      "id": 3
    }
  ]
}

    // This adds new cards to the server.
function addPurseCard(purseObj) {
    console.log("this is purse Object", purseObj)
    fetch("http://localhost:3000/purseData/purseObj", {
        method: "POST",
        headers: {
            "Content-Type": "application/json",
            "Accept": "application/json"
        },
        body: JSON.stringify(purseObj)
    })
        .then(res => {
           if (res.ok) { console.log("POST request successful!!!") }
           else { console.log("POST request unsuccessful") }
           return res
        })        
        .then(res => res.json())
        .then(newPurseObj => console.log(newPurseObj))
        .then(newPurseObj => createPurseCard(newPurseObj))
        .catch((error) => console.log(error))
}

这是 console.log 的输出。它显示了我试图添加到服务器的数据：

下面是我得到的错误：

我尝试单步执行调试器，我可以看到数据在移动，但它以 Post 请求错误结束。