A Plex account is basically your personal identity for things associated with Plex. You use it to sign in to the plex.tv/link , the support forums, and Plex apps. ... You can use the top menubar on the plex.tv website to sign in, sign up for a new account, or access account information if already signed in . You'll be presented with a 4-character code, which is what you'll use to connect the app with your Plex account. In your browser on your desktop or mobile device, go to and ensure that you're signed into the appropriate Plex account. Enter the 4-character code and submit.