Mods are usually distributed as zip archives. They need to be unpacked into the Mods/ subfolder of the game install folder (each mod will have it’s own folder inside Mods/ folder). If you installed the game from MS store, instead unpack the mods into My Documents/kingdomcome_mods.
You can optionally place a mod_order.txt file in the Mods/ folder. If you do this, only mods listed in this file will be loaded, in the order they are listed. The file should contain names of folders containing mods, exactly one per line. If a mod_order.txt file doesn’t exist, mods will be loaded in alphabetical order.