Well, it did just that by not having it as a menu selection.
Though the current versions of the software do it by graying out the icon for whatever is out of stock and making it unselectable, so this was either an older version of the software or wherever you were had deliberately locked out the flavor.
It was in the menu selection. No indication as to what was available and what wasn’t. I should have known better because I was surprised by the long list of selections. We found it in Parkersburg, WV - not exactly a tech savvy town. Maybe the franchise owner didn’t have it configured properly.