To do Alt + L E on Mac in Excel, download and install Accelerator Keys, then press Option, followed by L, E.
Command: Excel Add-ins
This is how to do Alt + L E 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 e opens the Excel Add-ins dialog specifically for managing traditional Excel add-ins (.xlam files). This allows you to browse, enable, or disable Excel-specific add-ins that extend the application’s functionality.