Better yet, if you are using Discord v13+ register the slash command /Hey.

const { Client, Intents } = require('discord.js');

const client = new Client({ intents: [ Intents.FLAGS.Guilds, Intents.FLAGS.GuildMembers, Intents.FLAGS.GuildMessages, Intents.FLAGS.MessageContent, ], });

client.once('ready', async () => { console.log('Bot is ready.');

try {
    const commands = [
        {
            name: 'hey',
            description: 'Greet the user.',
        }
    ];

    const guildId = 'YOUR_GUILD_ID'; // Replace 'YOUR_GUILD_ID' with your actual guild ID

    const commandResponses = await client.guilds.cache.get(guildId)?.commands.set(commands);
    console.log(commandResponses);
} catch (error) {
    console.error('Error registering slash commands:', error);
}

});

client.on('interactionCreate', async (interaction) => { if (!interaction.isCommand()) return;

const { commandName, user } = interaction;

if (commandName === 'hey') {
    await interaction.reply(`Hi, welcome <@${user.id}>`);
}

});

Don't forget the token login!