how do I know if im getting my ea play rewards on apex

@pathysbigwinney there are no current rewards for Apex Legends through EA Play, when new promotions are active, you can find them here: https://www.ea.com/ea-play/member-benefits#current-rewards

However, as @YourWatson mentioned, you can check the in-game store and you will see a discount for Apex Coins, that means your EA Play is active and you can get a discount for the purchases.