Ok, so you must go into map maker. In the map tab, under where you test/save/export, there should be a checkbox for the portal. It's automatically checked. Next, find the place where you want the portal to be. Run the arrow to the exact spot, and you'll notice coordinates at the bottom of your screen. Don't move your arrow while you write all of them down on a piece of paper. Next, type in the coordinates where it tells you to. (First number: X, second number: Y, third number: Z, "Yaw": Arrival yaw) Hope this helps.
