Adding image in the sun

I need to create a sky similar to that of the reference image. I tried the materials but I did not succeed. Somebody knows some way to do it, because I have no idea how to do it. The idea is to stay in the sun so I tried to insert via material without success if someone knows some way to do this and wants to share thank you.

NOTE: I intend to use the sky of the own engine because it already has everything configured