On the Account Details screen, look for the option that says Tapping this will take you to the wallet management page.
If you have a physical gift card or a digital wallet code, follow these steps in the app: how to redeem steam code on mobile
The good news? You don’t need a computer to add funds or games to your Steam account. Everything can be handled right from your smartphone. On the Account Details screen, look for the
So, you just received a digital gift card or a game key for Steam, but you’re nowhere near your PC. Maybe you’re at work, on the bus, or just lounging on the couch. You don't want to wait to start the download—you want to redeem that code now . On the Account Details screen