To do Alt + L M on Mac in Excel, download and install Accelerator Keys, then press Option, followed by L, M.
Command: Macros
This is how to do Alt + L M 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 m opens the Macros dialog box. From here you can view, run, edit, or delete macros in your workbook. You can also step into macros for debugging or create new macros.