How to use 360 ​​image as skybox in SceneKit?

I am using Xcode 8 and Swift 3 with SceneKit

I am making a game that takes place on a floating island in the sky. I want the background to be a beautiful sky with clouds and I want it to move accordingly when the camera moves like a skybox.

I can use an array of 6 images that wrap around to make a skybox, but I can't find any good ones online, nor any good generators to create them. I can find good 360 images like this one . My question is, how can I use an image like the one above to create a skybox in SceneKit? I'm sure it's possible because Apple has this on their website:

https://developer.apple.com/documentation/scenekit/scnmaterialproperty/1395372-contents

(You need to scroll down a bit to see it)

So, is there a way to do this, and how? Thank you. Any help is appreciated.