Problems with -audiomixer in shortcut for attenuation overrides

I was attempting to add steam audio occlusion into my project when I noticed the “attenuation overrides tab” is missing for me in UE 4.20.1. I was following this [question thread][1] but when I try to -audiomixer in the shortcut under target I get this.

248782-problem-with-shortcut.png

This is what I have written in my target

Any idea on what could have gone wrong?

SOLVED: Make sure that UE is closed completely and there is a space after the " then -audiomixer