How to download a whole book-pdf from a site for online reading?

Question

Electronic books

Tell me, please: there is a paid library that provides a book in pdf format for online reading only, that is, in paginated form. Is it possible to download the entire pdf file with one link? I must say that the address is tricky - when paging, the address does not change, but only the page is loaded, and the file itself with the pdf extension is not indicated in the address, but only a set of symbols, such as: ...book/35424-23

Answer 1

As far as I can see, the site does not display pdf on the screen, but the most common html, which is loaded in portions.
https://reader.lecta.ru/demo/7980/data/Chapter2.xhtml