To link a subscription purchased from MLB.com
For PlayStation® 4, the MLB app is available in the "TV and Video" menu.
After you have launched the MLB app for the first time, you will be asked to enter your MLB credentials in order to access live or archived games. Enter your credentials either by clicking on a live or archived game, or by clicking the "My Account" tab. Enter your MLB email and password using the virtual keyboard on your PlayStation® app. Once completed you can access live and archived games via MLB.TV on your PlayStation® system.