I understand the frustration because the MediaWiki API is a lot denser than the ones used for the other challenges. I’m not sure if you’ve used the API sandbox, but it’s very useful:
As for this challenge, you need to use a generator, which returns search results. In the sandbox, select action as query. Then in the sidebar, select action=query. Also select format as JSON. (Do this in the API sandbox)
You’ll have a bunch of options in the query menu now. Since we want extracts of pages from our query, select the “prop” as “extracts”. However, what extracts do you want? To get this, scroll down to “Generator”, which will have a drop-down menu. Select “search”, as we want to search for a term and get results for it. Generators in the MediaWiki API return several pages depending on which property you want.
Now you’ll have two other options: generator and extracts. Since this is a project I’ll guide you to the appropriate links to use these properly.
For extracts: https://en.wikipedia.org/w/api.php?action=help&modules=query%2Bextracts
For generator, don’t bother changing anything other than the limit. The gsrsearch field is the text you want to search. Look at the extracts article to know what to select. Once you’re done, you can get the correct api url and use it as usual with JQuery. Just use the sandbox and you’ll be ready in no time.