There are two ways to enter the "Customize Wall" interface:
1.Click "Customize-Customize Wall" in the left catalog, select the wall you want to edit, then you can enter the customize wall interface. You can exit the background wall interface by clicking "Complete Customize Wall"
2.You can also switch to the 3D view mode, left-click to select the wall, and click "Customize Wall" to enter the background wall environment. 
