Ffmpeg drawtext how to set the direction from right to left

Question

I write Arabic text in a video and it works fine, but the problem is that the Arabic language is written from right to left so the text should be aligned from right to left, I get the text as follows and it should be like this  my code

 

ffmpeg -y -i input.mp4 -vf "drawtext=text_shaping=1:fontfile=C\/:/Windows/Fonts/tradbdo.ttf:\
textfile=text-new.txt:fontcolor=white:fontsize=40:x=w-tw:y=h-50*t:" -c:v libx264 output.mp4