Realms is a subscription for a personal multiplayer server to be used with supported versions of Minecraft (game sold separately) on PlayStation® and other supported platforms on which you own the game (Minecraft Java Edition not supported). To cancel, see “How to Cancel” below. 
HOW TO CANCEL:
From a PS4™ System:
Sign in to PSN, then go to [Settings] > [Account Management] > [Account Information] > [PlayStation Subscriptions]. After selecting the subscription you want to cancel, select [Turn Off Auto-Renew].
From a computer:
Visit https://account.sonyentertainmentnetwork.com, sign in to PSN, and then go to the Subscriptions Management section. After selecting the subscription you want to cancel, cancel the automatic subscription renewal. Call Consumer Support on +1 877-971-7669. 
You need to log in to your Realm once every 60 days for the Realm to remain active. PlayStation®Plus membership is required to play on PlayStation® (sold separately). If your subscription is inactive for more than 18 months, your Realms data will be deleted from the server. ISP fees may apply. Realms discounts cannot be combined with other offers and are not redeemable for cash; Requirements, features, online services or subscription are subject to change and/or retirement. Subject to the Microsoft Services Agreement (microsoft.com/msa) and Realms End User Licence Agreement (https://www.minecraft.net/realms/terms/).