It seems like version 2.0.0 hasn't been released to pip yet, only these versions are available:
$ pip index versions capitains-nautilus
capitains-nautilus (1.0.3)
Available versions: 1.0.3, 1.0.2, 1.0.1, 1.0.0, 0.0.6, 0.0.5, 0.0.4, 0.0.3, 0.0.2, 0.0.1
When I use version 1.0.3 in my own project, I get the error message ModuleNotFoundError: No module named 'werkzeug.contrib'. I'd like to use capitains-nautilus exactly as in this repo in commit 86c9983.