Scripting in UXP Developer tools

So I'm trying to create a plugin in Photoshop using UXP developer tools.

What I'm trying to achieve:

When i click "Play Action", i want the photoshop to play the commands "command + j" and then "option + [". Command j performs duplication of the active layer, option j performs selection of backward layer.

I can do it manually but it's tiring to work on multiple documents by doing it manually.

If it's possible,

I would rather want the script to do

Constantly check for active selection > if there is an active selection > perform the above mentioned commands.

Please check the attached document.