Answers for "only you can see this message in discord bot discordjs"

see if discord message is in dm discord.js

if(message.channel.type === 'dm'){
	message.channel.send("Pog");
}

discord js message

client.on("message", message => {
    if (message.content.toLowerCase() === 'Hello') {
        message.channel.send("**Hey! What's Up?**")
    }
})
// This Will Print "Hey! What's Up?" When Someone Says "Hello" //