我正在尝试使用队列系统制作音乐机器人，尝试使用它时会不断出错

Question

这是我具有的机器人音乐功能的代码

// MORE CODE FOR MUSIC FEATURES IM PLAYING WITH


var servers = {};

function play(connection, message) {
    var server = servers[message.guild.id];
    const dispatcher = connection.play(ytdl(server.queue[0], { filter: 
        "audioonly" }));

    server.dispatcher = connection.play(ytdl(server.queue[0], { filter: 
    "audioonly" })).then(()=> {
        playing = true;
    });

    dispatcher.on('error', console.error);

    server.dispatcher.setVolume(0.2);

    server.dispatcher.on("end", function () {

        server.queue.shift();

    if (server.queue[0]) play(connection, message);
    else connection.disconnect().then(()=> {
        playing = false;
    });

});

}

Crashbot.on('message', async message =>{

    let args = message.content.substring(PREFIX.length).split(" ");

switch (args[0]) {
 case "play":
        if (!args[1]) {
            message.reply(`You need to put a link after ${PREFIX}play to add a song to the queue`)
            return;
        }
        if (!message.member.voice.channel) {
            message.channel.send("You must be in a voice channel to use this command")
            return;
        }
        if (!servers[message.guild.id]) servers[message.guild.id] = {
            queue: []
        }
        var server = servers[message.guild.id];

        if (playing) {
        server.queue.push(args[1]);
        return;
        }

        if (!message.guild.voiceConnection) message.member.voice.channel.join().then(function (connection) {
                play(connection, message);
        });
        break;
 case "skip":
        var server = servers[message.guild.id];

        if (server.dispatcher) server.dispatcher.end();
        break;

 case "stop":
        var server = servers[message.guild.id];

        if (message.guild.voiceConnection) message.guild.voiceConnection.disconnect().then(()=> {
            playing = false;
        });
        break;
}

})

，这就是我尝试使用音乐功能时不断遇到的错误。我已经仔细阅读了几次代码，无法弄清是什么原因造成的（我对编码很陌生，所以我对自己的编码不太了解，所以可能与它有很大关系）

(node:20560) UnhandledPromiseRejectionWarning: TypeError [ERR_INVALID_ARG_TYPE]: The "url" argument must be of type string. Received undefined
    at validateString (internal/validators.js:120:11)
    at Url.parse (url.js:159:3)
    at Object.urlParse [as parse] (url.js:154:13)
    at Object.exports.getURLVideoID (E:\Crashbot\node_modules\ytdl-core\lib\util.js:252:22)
    at Object.exports.getVideoID (E:\Crashbot\node_modules\ytdl-core\lib\util.js:285:20)
    at Function.exports.<computed> [as getInfo] (E:\Crashbot\node_modules\ytdl-core\lib\info.js:320:19)
    at ytdl (E:\Crashbot\node_modules\ytdl-core\lib\index.js:17:8)
    at play (E:\Crashbot\index.js:435:40)
    at E:\Crashbot\index.js:485:17
    at processTicksAndRejections (internal/process/task_queues.js:97:5)
(node:20560) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 1)
(node:20560) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.