How we can show shadow for 3D model in Model viewer using flutter

Question

I have a flutter application to display .glb files and able to load model along with environments. But not able to cast shadows for .glb model. Here is my snippet code

ModelViewer(
  backgroundColor: Colors.transparent,
  shadowSoftness: 1,
  posterColor: Colors.black,
  shadowIntensity : 1,
  cameraOrbit: '45deg 55deg 4m',
  cameraTarget: '0m 0m 0m',
  enablePan: true,
  exposure: 1,
  src: 'assets/Rebook_02.glb',
  ar: true,
  autoPlay: false,
  // touchAction: TouchAction.panY,
  // loading: Loading.eager,
  // skyboxImage: '../../assets/thatch_chapel_1k.hdr',
  alt: "A 3D model of an astronaut",
  autoRotate: true,
),

How I can pass cast shadows in flutter

I need shadows as shown in image

Thanks in advance