So in a future update I will be adding an in-game uploader and downloader. For now maps can be shared by simply copying the #.map file (and #.png file if you have an icon for it) located in: AppData>LocalLow>PolyDemons>The_RPG_Engine>Campaigns. There you will find a list of you campaigns as folders and inside are the map files. (you can also open and share your template maps by selecting the folder icon in the template menu). I hope this helps for now!