send a message using discord js

1message.channel.send("a")

1message.reply("message here");
2message.channel.send("message here");

1message.channel.send("test")

1client.on("message", message => {
2    if (message.content.toLowerCase() === 'Hello') {
3        message.channel.send("**Hey! What's Up?**")
4    }
5})
6// This Will Print "Hey! What's Up?" When Someone Says "Hello" //

1message.channel.send("A message!");
2message.reply("A message to the sender!");