Applescript for batch saving PowerPoint files into PDF

PPTtoPDF.scpt

# This is an update of codes from a Reddit post. The post is locked or otherwise I will just post this there!
# https://www.reddit.com/r/osx/comments/4gg3t3/batch_converting_powerpoint_2016_to_pdf_in/
# It is recommended that you also sep up a filter (on Automator) to make sure the file format is compatible.

on run {input, parameters}
	tell application "Finder"
		
		set theItems to input
		
		repeat with itemRef in theItems
			
			set theItemParentPath to (container of itemRef) as text
			set theItemName to (name of itemRef) as string
			set theItemExtension to (name extension of itemRef)
			set theItemExtensionLength to (count theItemExtension) + 1
			set theOutputPath to theItemParentPath & (text 1 thru (-1 - theItemExtensionLength) of theItemName)
			
			tell application "Microsoft PowerPoint"
				launch # required, or PowerPoint will return with parameter error
				open itemRef
				
				tell active presentation
					
					save in theOutputPath as save as PDF
					close
					
				end tell
				
			end tell
			
		end repeat
		
	end tell
end run

# Running this script sometimes requires additional authorization of file access to PowerPoint.
# Any idea how to remove that prompt to grant file access will be appreciated.