如何锁定提到的频道？Discord.py

import discord
from discord.ext import commands

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

@bot.event
async def on_message(message):
    if message.content.startswith('!lock'):
        # 获取提到的频道
        mentioned_channels = message.channel_mentions
        if len(mentioned_channels) > 0:
            # 锁定提到的频道
            locked_channel = discord.utils.get(message.guild.channels, id=mentioned_channels[0].id)
            if locked_channel:
                # 设置频道为只读模式
                await locked_channel.set_permissions(message.guild.default_role, send_messages=False)
                await message.channel.send(f"已锁定频道 {locked_channel.mention}")
            else:
                await message.channel.send("无法找到该频道")
        else:
            await message.channel.send("请提及要锁定的频道")

bot.run('YOUR_BOT_TOKEN')