How to apply such an effect?

Question

Design

Hello! Guys, how can I make such a square effect and blur around the edges in FS?

Answer 1

New layer
Draw a square
On the square apply the shadow effect
Render the layer
Delete the square
Remains the shadow of the square without the square itself

Answer 2

Draw a shape,
Set the "FILL" of the shape layer to zero,
Apply a drop shadow.