How do you make/download a curved background image?

I’m working on a high rise archviz project and would like to show the skyline surrounding the building. The best example of this I’ve seen is in this video I have access to the building so I’m able to go take a panorama image but I have no idea how to go from panorama to UE background. If there are downloads of generic city skylines that would be a great place to start as a proof of concept. I don’t believe this is a skybox but correct me if I’m wrong. I’ve been working with UE for only a week so the more basic explanation the better. Thank you!