orientation property
Rotates the model to the orientation specified by roll, pitch, yaw Euler angles, where yaw is first applied about the Y-axis, then pitch about the new local X-axis (positive is front-down), then roll about the new local Z-axis. If specified before the model loads, automatic camera framing will take this change into account; otherwise the updateFraming() method must be called manually.
<model-viewer>
official document: https://modelviewer.dev/docs/#entrydocs-scenegraph-attributes-orientation
Implementation
final String? orientation;