How to graceful-exit on Truenas?

No. To check the status you need to execute this command:

If your node was online since the start of the Graceful Exit, it should print the receipts of the successful Graceful Exit, otherwise you need to wait more. The mandatory requirement is to be online for the next 30 days after calling it.
If you failed to keep it online, you will get a disqualification message instead right on your dashboard.