There are task-oriented websites where you can get bids for specific small programming tasks.
But given it’s all of 134 entries, and given the relative complexity of this task (searching an OCR of an image stored in a PDF container, seeking some amount of text immediately following some target text), somebody can probably do that task manually more cheaply and more quickly than an app can be written and debugged and tested and explained and supported. Maybe using Quick Look here, rather than launching Preview for each file.
If you want to outsource this, various task-oriented websites (including Amazon) offer these “Mechanical Turk” services, as well.
For programming, I’d usually use bash or zsh here and not AppleScript, but shortcuts has access to Live Text (OCR) available in macOS 12 and later.
https://blog.greg.technology/2024/01/02/how-do-you-ocr-on-a-mac.html
Here’s some Swift code that uses Live Text (OCR), from an image (not a PDF): https://github.com/MatthiasWinkelmann/macocr/blob/main/Sources/macocr/Runner.swift
Adobe reportedly has tools:
https://www.adobe.com/acrobat/hub/use-ocr-to-read-text-from-image.html
But absent somebody that has this PDF-receipt-scanning-text-retrieval app already written, this is going to be faster to do the rename of the 134 files manually. And purchasing that hypothetically-already-existing app may still be more costly to purchase than a manual rename process iterating 134 files.
PS: Spotlight may be able to pick up this text automatically on recent macOS too, so you may be able to ignore all of this renaming work, using a Spotlight to search for the name of the party associated with the receipt when you need it. If you’re on macOS 12 or newer, try it with your particular image-containing PDF files.
PPS: yeah, if you’re just getting started with scripting, probably avoid using spaces in file names with scripts.