Can I redeem a PSN code from my phone?

Yes. You can redeem PSN codes on your phone in two ways. Using the PlayStation App (iOS/Android): open the app, tap the store icon, scroll down, and tap Redeem Code. Using a web browser: go to store.playstation.com, sign in, click your profile icon, and select Redeem Code. In both cases the content syncs to your PSN account and will be available on your PS5 or PS4 when you're ready.