@GruntGeorge I know that but what do I need to do that?

Hello there, I am a beginner at Sfm and I want to do a short movie with some maps from Gmod.
I will be using maps like this https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=164218457
and some other maps like Meet the medic for future videos.
The maps I want to use can be loaded into Sfm, but when loaded they have no lighting or sometimes are just plain black. When loaded a message also pops up saying this map is missing High dynamic range (HDR) lightmaps.
If someone knows how to fix this problem then please share, this is for a video I have planed, and would like to see become a reality.