Background image placement in landscape scenes


#1

Hello,

https://www.youtube.com/watch?v=9UwOrl036_A&t=59s 1:11-1:14
In time stamps above camera rotates slightly.
My question is how to set up background similar to the reference video, by background I mean Sky & smoke in the horizon. I assume I have to to matte paint the image in PS but how should I set it in the scene?
I do use HDRI for reflections and background image is meant only for view/composition.

Thanks.