如何在discord.py消息中获取提到的用户的id？

import discord
from discord.ext import commands

bot = commands.Bot(command_prefix='!')

@bot.event
async def on_message(message):
    if message.content.startswith('!mention'):
        mentioned_users = message.mentions
        for user in mentioned_users:
            user_id = user.id
            await message.channel.send(f"Mentioned user ID: {user_id}")
    
    await bot.process_commands(message)

bot.run('YOUR_BOT_TOKEN')

pip install discord.py