Thank you for your indulgence. As you can see, I don't know how to express this correctly, so I will spell it out.
In years past, I encountered computers with plastic cases that had places for a drive. All that was needed was to remove a screwed on strip of metal to open the bay.
Now I am in unfamiliar territory. This aluminum case with computer in it presents me with a place where a drive bay would be that is just an extension of the rest of the case with a smooth indentation that needs to be physically cut out to give access to a DVD drive.
The DVD drive can be heard to open inside the case. But until that indented piece is removed, the drive remains invisible, inaccessible, and unusable.