Easy enough especially if the text is always the same.
Write an AppleScript to try getting the text of the document. If the try fails, convert the document to pdf+txt (perform ocr). Once that’s done, you can use AppleScript to find the key phrase (“advice date”) and grab the 8 characters after and parse a date from it. Or just write it to a string “pay stub for 11/12/23.pdf” or whatever.
For more ideas, see this thread: Automatic Renaming of Receipts to RCPT YYYY-MM-DD for $XX.XX