Script Triggers do not work in IWP. The only exception is if you click a button on the screen and the button's script trips the trigger by going to a layout, entering a field, etc.
You'll need to find another way such as including the steps of your script in a button's script that takes the user to this layout in the first place.
Yeah that's what I thought, thanks! I have all the layouts on navigation buttons so I can add those script steps to that.