How to print long web page to one page pdf without seprate page

[rarksoca]

How to print long web page like this(https://comrademao.com/mtl/invincible-scanning-system/invincible-scanning-system-chapter-497) to one page pdf without seprate page like this Invincible Scanning System Chapter 497 – Comrade Mao.pdf 

i try to print using <button onclick="window.print()">Print this page</button>
but i get 6 pages pdf instead of one page pdf

Please tell me how to corretly print into one page without seprate page

i'm beginner so i don't know much 

sorry for my bad english,