How do I mask the strength of the UMG background blur component in ue4??

So I basically want to control the blur strength of the background blur component using an alpha image. I want the strength of the blur to be 0 in the middle and gradually increase sideways. I saw this option called “Apply Aplha to Blur” but I have no clue what it does or how to use it and set the alpha. Any help is highly appreciated. Thank you.

The background blur widget in UE5 supports adjusting Corner Radius.
If you want to apply a mask to control the blur region, see this plugin: Unreal BackgroundBlur With Mask - YouTube