To do Alt + P S P on Mac in Excel, download and install Accelerator Keys, then press Option, followed by P, S, P.
Command: Page Setup
This is how to do Alt + P S 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 + P S p opens the full Page Setup dialog with tabs for Page, Margins, Header/Footer, Sheet settings. This gives you complete control over all print settings in one place, including scaling, paper size, Print quality.