Thank for getting back to me on my question. 

You are right, it won't be the final k-1, just confirmed with them and now they want to keep the corporation open for a little longer maybe will close in 2024.

Therefore, I just need to report the sales of the business on the return, and pass the capital gain through the k-1s, and when the corporation liquidate then they will use their basis to figure out the gain or loss on their personal return?

Thank you in advance!