sphinx-tagtoctree | Sphinx extension for tag-based table-of-contents | Wiki library

The old project was build by Conda and I need to migrate it to using poetry.

One can use Poetry Init command to set up the toml configuration file. sphinx library was listed in the old Conda enviroment.yml file. And I need to add it by using poetry

In the step of adding packages, when I search sphinx there is only 9 candidates, in fact there are always 9 candidates. And there is no sphinx listed (see below) but when I put the name my self as it mentioned ,or the complete package name if it is not listed, I got the Value "sphinx" is invalid error