I've been trying to use tilemaps but it always shows me an error, how do I fix it or does it just not work? I also try to use Sprites like Boxes, Planes, Etc, but it doesn't show the texture, instead it shows a Red Texture Missing Error texture

Make 3D games in Construct 2 powered by Babylon.js · By
Tilemaps are not supported. Behaviors are meant for Tiled Background and Sprite objects.
If you do not require animation you should use Tiled Background. For Sprites you do have to add a spritesheet png with its filename matching the object's tag. Download baby3dEightDirExample.capx to see an example of this in action.