Mineflayer Catch the [msa] First time signing in ... Message

Question

I want to capture the [msa] First time signing in. Please authenticate now: .... message and send it using a DiscordJS client to a Discord server. However, I'm not sure how to catch it.

process.stdout.on('data', (data) => {
  const message = data.toString();
  if (message.includes('Please authenticate now:')) {
    console.log(message )
  }
});