Correct way in 2018 to open Facebook app via website link?

Question

Let me say first that I\'ve researched this for the past 4 hours. From various threads, I have seen that linking to fb://page/PAGEID is the OLD way of

Answer 1

Beware! I'm testing on android in September 2018:

fb://facewebmodal/f?href=FACEBOOKURL works, but doesn't display the page correctly - the header image is missed off and you end up in "about" with no way to like the app.

fb://page/PAGEID works fine in android and displays the page as intended. (for clarity this is the numeric pageid that the page owner can see in the about box in facebook)