To do Alt + J I A P on Mac in Excel, download and install Accelerator Keys, then press Option, followed by J, I, A, P.
Command: Add Pen
This is how to do Alt + J I A P 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 + J I A p adds a new pen to your Pens gallery. You can customize the pen’s color and thickness to create a drawing tool suited to your needs. The new pen will be available in the gallery for future use.