Oque significa "bih fye"?

It’s a very slang way to write “That bitch [is] fire, bro” Whatever or whoever they’re talking about is good

It's comical slang for "That bitch (thing) \[is\] fire (great) bro"

I'm English and I thought it was an attempt to write phonetically "that'll be fine, bro" as spoken by a Scot.

Please don't bother learning or using that. You'll come across like a moron to most people.

o bih normalmente é pra *bitch*… Nao sei se pode ter outro sentido dentro da collab. Fye é fire mesmo

It means "bitch fire," which means "hot/attractive woman." If the sentence was written with proper spelling, it would be, "That bitch is fire." American slang can be very daunting to English learners

"be fire" (usually something like "is very cool")