If that is the case, I don't think that it should show how when you hover over Hvor, right?
The hints are shared, so not every hint is going to be applicable to every sentence.
'Hvor' can have the meaning of 'how' in sentences like:
"Hvor vanskelig er det?"
"How difficult is it?"
"Hvor langt må vi kjøre?"
"How far do we have to drive?"
Is there a way to know when to use each form? can you just use "Hvordan" in any place where "how" in English is used?
"How" translates to "hvor" when referring to the degree/length/amount of something, as is the case in my examples above.
When it's referring to the way or manner in which something is done, "how" translates to "hvordan".