Invited but can no longer find where it is?

Um, how do I get to Vine? I chose and received my product and I'm trying to return to the menu to submit my review, but I can't find where to go? Searching brought me to amazon.com/vine which tells me all about the program like I'm not already in it. This was all done through my Amazon app so I know I haven't been scammed. Where the heck do I go to check in on new products available to try and post my review? Or do I just go through my order?