Is there a character for `biu`? biu is a fun onomatopoeia for the sounds guns and other shooting devices make.

This image is all over the net as the supposed character for biu

 

Is this correct?

I can't find much info on a ⿰口⿱比由 character.
Simple answer: No.
I know that such onomatopoeia is quite funny and useful, unfortunately they are quite recent that Chinese is too slow to generate a proper character for it.
The picture you showed is just a fake character that doesn't even exist.
So how do we express it?
Simple: Pinyin.
Another example: Duang.