You can check and set your owned wallpapers using the following steps:
■ How to Check Wallpapers
Go to Shop → Lobby Wallpaper → Free / Normal / Limited / Event and select the category.
■ How to Set a Wallpaper
Select an owned wallpaper → Tap Use Wallpaper → Confirm it shows “In Use”.
※ The wallpaper must be displayed as “In Use” to be properly applied.
※ Multiple lobby wallpapers can be set and used simultaneously.