index.js

const { Client } = require("discord.js");
require("dotenv").config();

// Declares our bot,
// the disableEveryone prevents the client to ping @everyone
const client = new Client({
  disableEveryone: true,
});

config({
  path: __dirname + "/.env",
});

// When the bot's online, what's in these brackets will be executed
client.on("ready", () => {
  // Set the user presence
  client.user.setPresence({
    status: "online",
    game: {
      name: "me getting developed",
      type: "WATCHING",
    },
  });
});

client.on("message", async (message) => {
  if (message.author.bot && !(message.author.username == "Manager")) return;
  if (!message.guild) return;

  let channel = client.channels.cache.get("ENTER_CHANNEL_ID_HERE");

  if (message.author.username == "Manager" && message.author.bot) {
    if (message.content == "/muteAll") {
      for (let member of channel.members) {
        await member[1].voice.setMute(true);
      }
      await message.channel.send(
        "Sssshhhhhhhhhh ! Users muted by the Moderator !"
      );
    }

    if (message.content == "/unmuteAll") {
      for (let member of channel.members) {
        await member[1].voice.setMute(false);
      }
      await message.channel.send(
        "Discuss!!!!! Users unmuted by the Moderator !"
      );
    }
  }
});

// Login the bot
client.login(process.env.DISCORD_TOKEN);