Shadow problem

Hi

I want to set up a HDR scene .

Use the sphere to make Full 360 Hdr Scene (already this part)

But Have some issue about Ground shadow.

I want to make a Ground shadow like object in the Hdr Scene .

I first use the plane to make Transparent BUT Can’t to receive object on plane.

I want object shadow on the ground and can see through the plane.

How should i do?