In step 3 of the gsg for ecart it says to pick your connection(done) and select your table and unique column. When I get to this step, I can select my connection, but the slots for choosing your table and unique column are'nt highlighted. I can't choose anything to manage my orders. Did I possibly miss something in my cart.php? I'm doing digital downloads and have a column added to both my products table and my order details table. If I can't select my table in this step, how can I go forward to setting up the downloads link after purchase?