.dart

 Future<void> onPlaneOrPointTapped(
      List<ARHitTestResult> hitTestResults) async {
    var singleHitTestResult = hitTestResults.firstWhere(
        (hitTestResult) => hitTestResult.type == ARHitTestResultType.plane);
    var newAnchor =
        ARPlaneAnchor(transformation: singleHitTestResult.worldTransform);
    bool? didAddAnchor = await arAnchorManager!.addAnchor(newAnchor);
    if (didAddAnchor!) {
      anchors.add(newAnchor);
      // Add note to anchor
      var newNode = ARNode(
          type: NodeType.webGLB,
          uri:
"https://github.com/KhronosGroup/glTF-Sample-Models/raw/master/2.0/Duck/glTF-Binary/Duck.glb",
          scale: Vector3(0.2, 0.2, 0.2),
          position: Vector3(0.0, 0.0, 0.0),
          rotation: Vector4(1.0, 0.0, 0.0, 0.0));
      bool? didAddNodeToAnchor = await arObjectManager!
          .addNode(newNode, planeAnchor: newAnchor);
      if (didAddNodeToAnchor!) {
        nodes.add(newNode);
      } else {
        arSessionManager!.onError("Adding Node to Anchor failed");
      }
    } else {
      arSessionManager!.onError("Adding Anchor failed");
    }
  }