horizontal scroll appear at right by default

horizontal scroll appear at right by default

In mCustomScrollbar, I want to place the scroller at the right end by
default of horizontal position. so i tried this.
$('.content').mCustomScrollbar("scrollTo",'last', {horizontalScroll: true});
But this works for me, except the right position
$('.content').mCustomScrollbar({horizontalScroll: true});
What should i do to make the horizontal scroll appear at right by default