Android phone/tablet: Tap More (three little vertical dots) > Find in Page. Enter your search term and tap Search (magnifying glass). Matches are highlighted. To find all the matches on a page, use the markers on the scroll bar.
iPhone/iPad: Tap More (three little horizontal dots) > Find in Page. Enter your search term. Matches are highlighted. Scroll down to see them all.
Windows: Type Ctrl-F and type your search term into the field that appears at the top of the page.
MacOS: Type ⌘-F and type your search term into the field that appears at the top of the page.