Reactjs 错误400错误请求Spotify API Post请求

我正在开发一个web应用程序，用户可以搜索音乐，创建一个新的播放列表，然后将其保存到他们的Spotify帐户。我现在一直在用户Spotify上创建一个新的播放列表

    `        //userUd, playlistName, currentUserAccessToken are all defined 

fetch(`https://api.spotify.com/v1/users/${userId}/playlists`, {
              headers: {
                'Authorization': 'Bearer ' + currentUserAccessToken
              },
              contentType: 'application/json',
              method: 'POST',
              body: {
                "name": `${playlistName}`,
                "description": `You made this playlist with Jammming, a ReactJS web application built by Max Page`
              }
            }).then(playlist => {
              console.log(playlist);
              return playlist.json();
            }).catch(err => {
              console.log(err);
            })`

这里的目标是获得新的playlid，有人知道我为什么会收到400个错误请求吗？我做了GET请求，授权用户创建公共播放列表的范围，在不同的代码块中工作，如下所示：

`let scopes = 'playlist-modify-public';

 window.location.replace(`https://accounts.spotify.com/authorize?client_id=${clientID}&scope=${scopes}&redirect_uri=${redirectURI}&response_type=token`);`

---

提前谢谢

收紧你的身体。这就是为我修正相同错误的原因

fetch(`https://api.spotify.com/v1/users/${userId}/playlists`, {
          headers: {
            'Authorization': 'Bearer ' + currentUserAccessToken
          },
          contentType: 'application/json',
          method: 'POST',
          body: JSON.stringify({
            "name": `${playlistName}`,
            "description": `You made this playlist with Jammming, a ReactJS web application built by Max Page`
          })
        }).then(playlist => {
          console.log(playlist);
          return playlist.json();
        }).catch(err => {
          console.log(err);
        })`