Answer
$(x-2)^2=-4(y+3)$
See graph.
Work Step by Step
1. Based on the given conditions, the parabola opens downward, vertex $(2,-3)$, thus we have a general form $(x-2)^2=-4p(y+3)$
2. With $p=1$ (distance from vertex to focus), we have $(x-2)^2=-4(y+3)$
3. See graph.
