Publishers fully control access to their event grids. If you would like access to a publishers’ grids, you can request it by contacting your sales rep. If you do not have a sales rep, you can contact the publisher directly via their Contact Us page of their website. Access is granted to specific email addresses, which act as your ‘identity’ of sorts in Edelweiss. When you request access, be sure to let your sales rep or the publisher know which email address you use to log in to Edelweiss, as well as any other users at your organization who should have access.
Note: publishers tend to send authors to stores and libraries with whom they do business, which very much makes sense if you think about the purpose of these events. If you do not order directly through the publishers and/or do not have an account with a publisher, establishing such a relationship is generally a solid first step here. That is, of course, up to the discretion of the publisher.