Can you mod Incapacitating Roar on gse

cant seem to get
/cast [mod:shift,nochanneling] Incapacitating Roar
work it just shows the roar on bar but doesnt cast it, am i doing something wrong

EDIT: adding it to own action box made it work, thanks

Depends on Where you put that. Are you adding that to a variable and adding it to every action ahead of the normal cast line or just throwing it into a box on its own? Both of those are valid but will have different outcomes depending on what you want to do.