It seems that vtkLabelWidget is not being loaded.

I see that you’re currently using version 28.1.0, and it appears that vtkLabelWidget is not available in the Widget.Widget3D. According to your findings on GitHub, the folder exists but the import statement is missing. Are there any alternative ways to import LabelWidget other than using Widget.Widget3D.vtkLabelWidget?

Have you seen that LabelWidget example?

Yes, I checked the examples.
Currently, you are using the <script type="text/javascript" src="https://unpkg.com/vtk.js"></script> tag to load the vtk.js library. Previously, when using version 22.6.0, you were able to use vtk.Interaction.Widgets.vtkLabelWidget.newInstance(); . However, in the latest version, after transitioning to Widgets3D from Interaction, it seems that importing vtk.Widgets.Widgets3D.vtkLabelWidget is not working. From my understanding, starting from version 24.0, it appears that the import statement in vtk/Widgets/Widgets3D/index.js is missing the LabelWidget. Do I need to import it separately?

Understood, I just pushed a PR that should fix it.
Thanks for the report.