When printing this model, I used ABS because of its ability to yield to stresses which suits such a mechanical application. It's recommended, as this is done to the original part as well, to insert some kind of silicon flexible tube into the holes at both ends of the handle to make the clips spring back out more forcefully, which holds the handle more firmly in.
It's also recommended to print this handle flat on its side, so the layer lines are in parallel with the pulling force when someone uses the handle to pull the cart.