Skill-based tournaments gaming app using virtual currency to redeem only for gift cards and real prizes

I am developing a mobile gaming app where players can either collect the app's virtual currency through winning tournaments or by purchasing virtual currency, which will be used to purchase real prizes and gift cards/vouchers. The application will be cross-platform where players can access their account on other platforms outside of the mobile app.

My question is whether the purchase of the virtual currency would be treated as an IAP or not since there is a physical value of the virtual currency outside of the app because it can be used to purchase gift cards and other real prizes?

Any guidance would be greatly appreciated it. Thanks!