Simple GREP AppleScript Help

I'm new to AppleScripting and I need some help. I'm trying to script the simple GREP attached, but I'm having trouble trying to get it to search within the paragraph style: Bold. This is what I have to far. Any help is greatly appreciated!

tell application "Adobe InDesign CC 2019"

set find grep preferences to nothing

set change grep preferences to nothing

set find what of find grep preferences to ",$"

set change to of change grep preferences to ""

apply paragraph style using paragraph style "Bold"

change grep

set find grep preferences to nothing

set change grep preferences to nothing

end tell