I haven't used uv much yet but is seems that --extra-index-url is handled a little bit differently from the way pip does the search. It's defenitely more secure but as per uvdocs this means that libraries might not be found for some private indices. Also --extra-index-url is deprecated from uv CLI.
What I found though is that --find-links option does work.
So assuming your requirements.txt looks like this:
You should be able install Prodigy using uv using the --find-links option. --find-links is needed because Prodigy is using custom package index.
You should also be able to define prodigy as a dependency in a pyproject.toml e.g.:
Running uv pip install -e . should download Prodigy from our download server.
Is there any particular issue you're running into when trying to install Prodigy with uv?