hold up (one's) end (of the bargain)
To fulfill or attend to one's obligation(s) or promise(s) as agreed; to do one's agreed part in some arrangement. I've paid my share setting up this business—now it's time for you to hold up your end. Jackie didn't hold up her end of the bargain, so we're excluding her from the deal.
hold one's end up
to carry one's share of the burden; to do one's share of the work. You're not holding your end up. We're having to do your share of the work. Get busy. You have to hold up your end.