Transform point from DWG model coordinates to autodesk forge viewer coordinates (new WGS.LmvMatrix4 undefined)

I am trying to display a point on model displayed in the Autodesk forge viewer. However I am unable to figure out how to transform the point. I found the next question that seems to resolve this question:

Transform point from DWG model coordinates to autodesk forge viewer coordinates

When I try to use the function of this question:

var vpXform = viewer.model.getPageToModelTransform(viewportId).clone();
var invVpXform = new WGS.LmvMatrix4(true);

invVpXform.getInverse(vpXform, true);

var ptInCadX = ...;
var ptInCadY = ...;
var verticesInViewer = new THREE.Vector3().set(ptInCadX, ptInCadY, 0).applyMatrix4(invVpXform);

It shows the next error: Uncaught ReferenceError: WGS is not defined

And if I try it without the WGS.LmvMatrix4, it shows the following error: Uncaught ReferenceError: new LmvMatrix4 is not defined

I’m using the latest version of the Forge Viewer, v7.Can someone help me finding what am I doing wrong?

Thank you very much.