How should I reference a user on discord when coding a bot with Autocode?

So I tried msg.author.user and message.author.username and message.author.user and it always returns message is undefined or msg is undefined but everywhere I look, it just tells me to to do the previously stated 3 things. I am trying to get the bot to respond to a command with text and it doesn’t work. I’m using Javascript on Autocode to make the bot.