I went through the process of securing an ESA letter for my dog, and it really is wild how many fake registries pop up when you search online. I almost bought one of those instant ID kits before realizing they hold zero legal weight. I actually spent a whole afternoon looking up different services and even ended up checking https://support-pets.pissedconsumer.com/customer-service.html just to see if other people had issues getting their landlord to accept documents from certain telehealth sites.