It looks like the current version of jupyterlab-prodigy doesn't yet support Jupyterlab 3. Are there plans to update it?
ValueError: The extension "jupyterlab-prodigy" does not yet support the current version of JupyterLab.
Ah, I think I missed the stable v3 announcement for JupyterLab. But yes, we definitely want to support the new version and I hope there's not too much that needs to be changed. I'll put in on our list of enhancements 
(Btw, the extension code is here so if there's anything obvious that needs to be updated, feel free to submit a PR: GitHub - explosion/jupyterlab-prodigy: 🧬 A JupyterLab extension for annotating data with Prodigy)