OK so here’s a handy dandy chart to easily use any of the seven modes in any key…
(Bb=A#, Eb=D#, Ab=G#, Db=C#, Gb=F#)
Just find the mode and key you want on the chart and set the arp to the major mode in the corresponding key shown on the left… 
-I copied this chart from the Internet, It shows several flat keys at the bottom left, on the OT the key can only be set in sharps so I listed the equivalent sharp keys at the bottom just in case…