Discord.js |当我尝试运行我的Discord.js命令时，它会显示错误"Cannot read property 'execute‘of undefined“

const Discord = require('discord.js');
const client = new Discord.Client();

const commandName = {
  name: 'commandName',
  description: 'Command description',
  execute(message, args) {
    // Command logic here
  },
};

const commands = new Discord.Collection();
commands.set(commandName.name, commandName);

client.on('message', (message) => {
  if (!message.content.startsWith(prefix) || message.author.bot) return;

  const args = message.content.slice(prefix.length).trim().split(/ +/);
  const command = args.shift().toLowerCase();

  if (!commands.has(command)) return;

  try {
    commands.get(command).execute(message, args);
  } catch (error) {
    console.error(error);
    message.reply('An error occurred while executing the command.');
  }
});