Using HTTrack to download links only under a certain subdomain (nothing external)

So, this is what I am trying to download - https://www.slader.com/textbook/9781337624183-calculus-9th-edition/

Looks fairly simple, I tried adding a few lines to "scan rules" to force it to download everything under it but for some reason, the entire process finishes under 10 seconds and it doesn't go further than just downloading the aforemention link itself. For example, in addition to having https://www.slader.com/textbook/9781337624183-calculus-9th-edition/ itself, I would like to have all links originating from it, such as https://www.slader.com/textbook/9781337624183-calculus-9th-edition/311/ too. Essentially, everything that starts with the first link above (including embedded pictures originating from other domains, but no external links beyond that point).