You can't. This script uses DC's search engine api/v9/search to search for messages, DCs own API does not have this option to find reactions you've made, so you can't find reactions like message/channel IDs.
The only way to do this is to make a crawler to read the entire chat history, which reads the chat line-by-line. And this will be very taxing on the DC API because it has to read every message to see if you reacted to it. It'll take a long time depending on your DC reaction rate.
There are probably bots that can do this, but it still has to crawl and you'll be flagged no doubt.
Originally posted by @AerialJustice in #734 (comment)