Discord 尝试添加角色时出现机器人错误

Question

Trying to make a "mute command" comes up with TypeError: Cannot read property 'add' of undefined If you could help me Thanks:)

module.exports = {
    name: 'mute',
    description: 'f',
    execute(message, args) {
        const taggedUser = message.mentions.users.first();
        const mutedRole = "800612654234337281"
        if (!message.mentions.users.size) {
            return message.reply(`Oh, thats unexpected you haven't tagged anyone.`);
        }
        message.channel.send(`${taggedUser} has been muted`);
        taggedUser.roles.add(mutedRole);
         
    },
};

Here is the "main file" if there is an issue with this

const fs = require('fs');
const Discord = require('discord.js');
const client = new Discord.Client();
const { prefix, token } = require('./config.json');
client.commands = new Discord.Collection();
const commandFiles = fs.readdirSync('./commands').filter(file => file.endsWith('.js'));
for (const file of commandFiles) {
    const command = require(`./commands/${file}`);
    client.commands.set(command.name, command);
}

client.once('ready', () => {
    console.log('Online');
});

client.on('message', message => {
    const args = message.content.slice(prefix.length).trim().split(' ');
    const command = args.shift().toLowerCase();
    if (!client.commands.has(command)) return;

    try {
        client.commands.get(command).execute(message, args);
    } catch (error) {
        console.error(error);
        message.reply('there was an error trying to execute that command!');
    }
});
client.login(token);

Answer 1

This will not work because discord user and guild member both are completely different methods. You cannot add roles to discord user in any guild (unless your bot is in the said guild), you can only add roles to guild member.
replace:

message.mentions.users.first()

with:

message.mentions.members.first()

Learn more about:
Discord User
Guild Member