How can I make a background GUI with a pulsing drop shadow effect?

I am not sure how I can make a black background (frame) GUI have a white drop shadow that sort of pulses? Best example I can think of would be the starting page of Deepwoken for those who have played Deepwoken.

below is a screenshot of the background with the white drop shadow, however those of you who have played the game know that it pulses in and out

It’s probably just an image of a blurred circle. Either change its size or transparency in a tween.

You could pretty closely follow the “Looping a Tween” example on this page: TweenService | Roblox Creator Documentation

Just change the GUI’s size or transparency instead of a part’s position.

I believe that it was a circle image that had a low transparency that they tweened to pulse. Thanks for the article!