YES, NO but where is CANCEL ?

Where has the ‘Cancel’ button gone?
After accidentally clicking the close button, how can you carry on working if you don’t want to save or lose all the work you’ve done?
In this case, I needed to save this file under a different name (save as).

I had the presence of mind to duplicate the file in the File Explorer before saving it, but it’s not a user-friendly interface !!!