data-rotation

<mr-entity data-position="0 -1 0.5" data-rotation="90 -30 180"></mr-entity>
<mr-light data-position="0 -0.1 0.15" color="white" intensity="0.5"></mr-light>

Rotation can be attached to an mr-entity using data-rotation, it has a specific 3D value:

data-rotation

Sets the rotation of an entity in the 3D space, relative to its parent.

Value: a string of 3 numbers in degrees, separated by a space.