As Colin says that is correct. I do want to add that you do need to set a password as well but that can be anything you want.
If you have multiple machines then you can set workernames by adding something to the username for each miner like this:
38HRDQeecdfQnCyrnLEtKJGnEsrLG3XUCt.worker1
38HRDQeecdfQnCyrnLEtKJGnEsrLG3XUCt.worker2
etc
So a point after the btx address and then a specific name (you can choose which) per miner
You don't need to do this but it is handy if you want to monitor different machines and how well they are mining because with these extended usernames you get stats per worker on the ckpool site.
One question, what data can you extract to check if the Asics are doing well?
Thanks in advance
Only the hashrate. Basically it is a quick way to see if any of your machines are underperforming (use 1D or 7D average) instead of logging into each one separately*. If one is then you can log into that machine and troubleshoot.