In iphone latest version, where is the "go back to previous page" button?

Typical use: in the pdf, there is a link. Clicking that link, I can jump to a different page. Then "go back to previous page" button help me to nativgate back to the prevous page.

Some one claims iphone version has such button. However, I cannot find the button. If there is such button, may anyone share a screen shot? I am desperately looking for it and I appreciate your help. Thank you.