When I do allpages request  (https://wiki.swimrankings.net/api.php?action=query&list=allpages&format=json) I get only some 4 non-important pages

There are no pages like rankingDetail that could contain the data. I can't even get those pages to see if data can be extracted from them.

If you look, for example, parse request for Main_Page:
https://wiki.swimrankings.net/api.php?action=parse&page=Main_Page&prop=text&formatversion=2&format=json
you can see that it returns HTML content

There are no other pages except these 4 pages above so I cannot fetch any swimmer's data.

Can I somehow get data for individual swimmers... ?

Vladimir