To do Alt + L S on Mac in Excel, download and install Accelerator Keys, then press Option, followed by L, S.
Command: Scroll Bar (Form Control)
This is how to do Alt + L 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 + L s inserts a Scroll Bar form control. Scroll bars allow users to select a value from a range by dragging a slider. You can link it to a cell to capture the selected numeric value, useful for interactive dashboards and what-if analysis.