예시:

const { Client } = require("discord.js"),
    { getVoiceStream } = require("d-tts");

const client = new Client();
client.login("Token");

client.on("ready", () => {
    console.log("Bot is Ready.");
})
.on("message", m => {
    if (m.content === "test") {
        message.member.voice.channel.join().then(connection => {
            const stream = getVoiceStream("테스트 TTS", "ko-KR");
            const dispatcher = connection.play(stream);
            dispatcher.on("finish", () => message.member.voice.channel.leave());
        });
    }
});

필요한 모듈:

discord.js
@discordjs/opus
ffmpeg-static