Hello, niches can be achieved through the selection of finished models or by making them on the top and wall. In the 5plus version, you can also drag and drop in the floorplan - structure - niche. The specific operation steps are as follows:

Method 1: Select from Cloud Materials - Decoration - Furnishings - Wall Decorations - Niches;

Method 2: You can make holes through the functions of top and wall or free modeling. The specific operations are as follows.

Animated gif of the free modeling operation is as follows: Animated gif of the top and wall making niche operation is as follows:

Method 3: In the 5plus version, drag and drop in the floorplan - structure - recess.

If you need to select the niche in the 3D or WT view for adjustment, you can hold the ctrl key and left-click the niche, and adjust it in the parameter panel on the right

You can also ungroup the niche and adjust it separately

The animated operation is as follows: