我在做一个不和谐音乐机器人，我写了下面的代码:

module.exports = {
    name: 'play',
    aliases: ['p'],
    description: 'Play a song',
    guildOnly: true,

    execute(message, args) {
        const ytdl = require("ytdl-core");
        
        var servers = {}
        var server = servers[message.guild.id];
        var queue = []
        
        function play(connection, message){
            var server = servers[message.guild.id];
            var str = String(message)
            var key = str.split(/\s/);


            // If user inputs skip, skip the song
            try {
                server.dispatcher = connection.play(ytdl(queue[0], {filter: "audio"}));
            } catch (error) {
                if (key[1] == "skip") {
                    server.dispatcher.destroy();
                } else {
                    message.channel.send("You need to provide a correct url!");
                    console.log(error)
                    }
                return;
                }

            queue.shift();

            server.dispatcher.on("finish", function(){
            if (queue[0]){
                play(connection, message);
            } else {
                connection.disconnect();
            }
        });
        }
//------------function ends here-------------------

        if (!args[0]) {
            message.channel.send("You need to provide a link!");
            return;
        }

        if (!message.member.voice.channel){
            message.channel.send("You must be in a voice channel to use this command!");
            return;
        }

        queue.push(args[0]);

        if (!message.guild.voiceConnection) message.member.voice.channel.join().then(function(connection){
            play(connection, message);
        });
}}

每当我运行代码时，它总是给我错误

TypeError:无法设置未定义的属性“dispatcher”

错误出现在第22行，它是

server.dispatcher=connection.play(ytdl（队列[0]，{filter:“audio”}））；

据我所知，当一个变量被声明但还没有被赋值时，它会抛出错误。但是我只是在它上面赋了值，我不能理解为什么它会给我错误。

顺便说一下，歌曲队列和跳过功能从来没有工作过，所以如果有人能帮助我纠正错误，我将非常感激，非常感谢！