In DSPMIXFX on mac, what is the shortcut key for roofback?

I’m using mac and ur-rt2. Because I’m blind and screen reader doesn’t read the menu of dsp, I cannot turn on and off roofback function. Is there a shortcut key for roofback? Or is there any way I can view all the list of shortcut keys? SIf not, can I make my own shortcut keys in this program?