In Quest 3 in XR, how can I place objects in specific locations without depending on the room?

In Quest 3 in XR, how can I place objects in specific locations, either marked by a QR code or in some other way?

I need to be able to place certain 3d elements in specific places regardless of how the room is and without being deconfigured, it would be ideal with a qr system or visual elements that mark the position in the application.

Thanks!