To do Alt + M S on Mac in Excel, download and install Accelerator Keys, then press Option, followed by M, S.
Command: Use in Formula Menu
This is how to do Alt + M S on Mac in Excel with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with Excel.
Alt + M s opens the Use in Formula dropdown menu in Excel’s Formulas tab. This menu displays all named ranges and allows you to quickly insert them into your formulas without having to remember or type the exact name.