How can I import a Steam Trailer for e.g. a game purchased from Epic?

[Soop]

I've just imported a bunch of Steam trailers after upgrading to Pro, but it seems to have only worked for games originally purchased via Steam.  Is there an easy way to pull the trailers for the other half?  It's a fair few games, so I don't want to do it manually if I can avoid it.

As an aside, is there also a way to move the order of the images and video in the game view?  I'd rather have the video display after the theme image