UV unwrap ico Sphere How can I UV unwrap ico Sphere in order to project a 360 image on its inner surface?

I need to use this model in Unity, so I have to be able to export UV layout along with the model.

The way I tried will cause a lot of distortion:
You don't actually need to UV unwrap your sphere at all. Just plug the Generated output of a Texture Coordinate node into your texture's Vector input, and set the projection (probably "Flat") to Sphere (or try Tube).

Edit: Missed the fact that this is for Unity. I will leave this answer here for others who just want to do it in Blender.