Can I change material of loaded gltf model?

CesiumJS
1 
var model = await Cesium.Model.fromGltfAsync({
    url: 'CesiumMilkTruck.glb',
    modelMatrix: Cesium.Transforms.headingPitchRollToFixedFrame(
        position,
        hpRoll,
        Cesium.Ellipsoid.WGS84,
        fixedFrameTransform
    ),
});
planePrimitive = scene.primitives.add(model);
const material = planePrimitive.getMaterial('Texture'); // getMaterial undefined

In the old post, there seems to be a getMaterial method, but in ver 1.105.1 there seems to be no getMaterial and it becomes undefined.
Is it possible to change the material of the model loaded with ver 1.105.1?
Specifically, I want to adapt the video element as a texture.

2

Any feedback?