How do you save as MS Office 2013?

I just installed a fresh copy of Libre (Version: (x64)) and it only seems to give an option to save in the older Office format (97-2003). Yet on this page link text more options are given than what I get on my version

Either select the Microsoft Excel 2007-2013 XML (.xlsx) file format from the SaveAs dialog, or just use the file name extension .xlsx when saving which automatically saves as OOXML.