问Spotify Web -为什么新创建的播放列表没有填充所选歌曲？

EN

const clientId = '6acd4fb43b3443c190e390753512049d'//Create a working Spotify Web API project to get the client id
const redirectUri = 'https://www.spotify.com/uk/'; //a redirect uri that matches value in the Spotify WEB API project page
let accessToken;

//below are manual entries for the playlist name and tracks (with unique spotify URI)
const playlistTracks = ["spotify:track:6UaHTPaVvS1rasCTUs64N0", "spotify:track:6bC1z4GVrswBEw0D2pOkbT"];
const playlistName = 'StackOverflow Jams II';

const Spotify = {
    getAccessToken() {
        if (accessToken) {
            return accessToken;
        }

        //check for access token match
        const accessTokenMatch = window.location.href.match(/access_token=([^&]*)/);
        const expiresInMatch = window.location.href.match(/expires_in=([^&]*)/);

        if (accessTokenMatch && expiresInMatch) {
            accessToken = accessTokenMatch[1];
            const expiresIn = Number(expiresInMatch[1]);
            // This clears the parameters, allowing us to grab a new access token when it expires
            window.setTimeout(() => accessToken = '', expiresIn * 1000);
            window.history.pushState('Access Token', null, '/');
            return accessToken;
        } else {
            const accessUrl = `https://accounts.spotify.com/authorize?client_id=${clientId}&response_type=token&scope=playlist-modify-public&redirect_uri=${redirectUri}`;
            window.location = accessUrl;
        }
    },

    search(term) {
        const accessToken = Spotify.getAccessToken();
        return fetch(`https://api.spotify.com/v1/search?type=track&q=${term}`, {
            headers: {
                Authorization: `Bearer ${accessToken}`
            }
        }).then(response => {
            return response.json();
        }).then(jsonResponse => {
            if (!jsonResponse.tracks) {
                return [];
            }
            return jsonResponse.tracks.items.map(track => ({
                id: track.id,
                name: track.name,
                artist: track.artists[0].name,
                album: track.album.name,
                uri: track.uri
            }));
        })
    },

    savePlaylist(name, trackUris) {
        if (!name || !trackUris.length) {
            return;
        }

        const accessToken = Spotify.getAccessToken();
        const headers = { Authorization: `Bearer ${accessToken}` };
        let userId;
        console.log(trackUris);
        console.log(accessToken);

        return fetch('https://api.spotify.com/v1/me', { headers: headers }
        ).then(response => response.json()
        ).then(jsonResponse => {
            userId = jsonResponse.id;
            return fetch(`https://api.spotify.com/v1/users/${userId}/playlists`, {
                headers: headers,
                method: 'POST',
                body: JSON.stringify({ name: name })
            }).then(response => response.json()
            ).then(jsonResponse => {
                const playlistId = jsonResponse.id;
                return fetch(`­https://api.spotify.com/v1/users/${userId}/playlists/${playlistId}/tracks`,
                    {
                        headers: headers,
                        method: 'POST',
                        body: JSON.stringify({ uris: trackUris }) 
                    })
            })
        })
    }
};

function savePlaylist() {
    Spotify.savePlaylist(playlistName, playlistTracks);
  };

savePlaylist();