register discord bot command

app.js

client.on('interactionCreate', async interaction => {
  if (!interaction.isCommand()) return;
  
  const { commandName } = interaction;
      
  if (commandName === 'ping') {
    const timeTaken = Date.now() - interaction.createdTimestamp;
    await interaction.reply(`Pong! This message had a latency of ${timeTaken}ms.`);
  } else if (commandName === 'holiday') {
    await interaction.reply(await calendar.getHolidayList());
  }
});

client.login(process.env.DISCORD_BOT_TOKEN);