To do Alt + J + P + T on Mac in PowerPoint, download and install Accelerator Keys, then press Option, followed by J, P, T.
Command: Transparency
This is how to do Alt + J + P + T on Mac in PowerPoint with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with PowerPoint.
Alt + J + P + T opens the Transparency gallery in PowerPoint. This allows you to adjust the opacity of your pictures, making them more or less transparent to create layered visual effects.