Set ReferenceImageLibrary at Runtime

I need to set the active ReferenceImageLibrary at Runtime. I've attempted the following:

Code (CSharp):

1. m_TrackedImageManager = gameObject.AddComponent<ARTrackedImageManager>();
2.  
3.         var newReferenceLibrary = Resources.Load("ReferenceImageLibrary") as XRReferenceImageLibrary;
4.  
5.         m_TrackedImageManager.referenceLibrary = newReferenceLibrary;

It does not seem to work.

Essentially I am performing two separate actions depending on the active ReferenceImageLibrary, so I need to set different Reference Image Libraries depending on user actions.