Script from Joshua Johnson's post on how to automate screencaps (https://mac.appstorm.net/general/applescript-automatically-create-screenshots-from-a-list-of-websites/)

URLs-to-screenshots.scpt

--Variables
set whichUrl to 1
set fileNames to "webshot"

--Get Number of URLs
tell application "TextEdit"
	set theCount to the count of paragraphs of front document
end tell

--Repeat this for every URL
repeat theCount times
	
	--Get the next URL
	tell application "TextEdit"
		set currentUrl to paragraph whichUrl of front document as text
	end tell
	
	--Open the URL in Safari
	tell application "Safari"
		activate
		set the URL of document 1 to currentUrl
		
		--Wait until it loads, then take a screenshot
		delay 5
		set picPath to ((POSIX path of (path to desktop)) & fileNames & "-" & whichUrl & ".jpg") as string
		do shell script "screencapture -tjpg " & quoted form of picPath
	end tell
	
	--Increase the counter for next time
	set whichUrl to whichUrl + 1
end repeat