Is there a way to have a UIGradient on the X and Y axis?

I want to put a gradient on the transparency of all sides of my UI. I have tried putting two UIGradients in the frame, but Roblox doesn’t allow me two have both enabled at the same time. I have looked all over the devforum on how to do this and have found nothing.

The reason I need this is because I am trying to make a shadow-type look without having to use images. Is there a way I can achieve this? Here is the .rbxm file for my UI.
ScreenGui.rbxm (3.4 KB)

for now we can’t use anything but shadow image, may I know why you don’t want to use image?

I don’t want to use an image because I like using UICorner and images can’t follow UICorner, but if I used a gradient and just copied the frame, I could make it work but also follow UICorner.