How to reproduce such an image?

[rmnkk]

I want to understand how to reproduce this gradient exactly. I tried to use a freeform gradient (see the second picture Asset 1@2x.jpg), but it did not achieve the dark yellow shade on the edges and the sharp angle on the right. What other options are there?

[Monika Gause]

Has the image been made in Illustrator in the first place?

Could be a result of Photoshop blurring or painting.

In Illutrator you could check out blur effects as well. Or gradient meshes.