The cli command should be **swh-identify**. Examples and the subheading show** swh identify** (without the dash).
Other places (the Pypi docs and Readme for developers) show the correct command.
https://docs.softwareheritage.org/devel/swh-model/cli.html
https://forge.softwareheritage.org/source/swh-model/browse/master/swh/model/cli.py