Well, I kinda figured it out, in a way, lol. Have a friend send you the unzipped mod file through Discord and then go to your nw.app folder and then either put the mod file in the "js" folder or the "data" folder depending on the mod file. Some mod files may require the person to edit certain parts of the "js" script such as the "Always win coin flip" mod which is very annoying to try and do on Macbook so make sure to read all mod descriptions before downloading. Mods such as the "Infinite saves" mod can be put directly in the "data" folder. You'll get the option to replace a map in the "data" folder, click replace and boom, there 'ya go. (To find the "nw.app" folder check properties on Steam, then right click on "game", open that with "show contents" or something of that sort.)
(Make a back-up of the "nw.app", "data", and "js" folders. Also, make sure to change the duplicated folder to the same name or the mod files will not load properly.)
Have fun. : )