I want to write google chrome extension code. but what I want to do is read the data of a site and intervene according to that data. For example, if a product is on sale on Amazon, if I type it with a command, will it automatically get it? I would like to emphasize that I will not take it, it has to take it automatically with the command I gave, so will it be able to take it by itself while I sleep? Is this possible with a java script?
"Edited again"
Yes, this is certainly possible.
I found 2 resources that you should read up on for this type of this type of thing: https://developer.chrome.com/docs/extensions/mv3/getstarted/ (Get started and learn how extensions work)
Modify HTML of loaded pages using chrome extensions (Manifest V2, maybe look around for something similar in V3?)