To get the name and authentication method, I imagine something like
mgmt_cli -r true show-users details-level full --format json | jq '.objects[] | [.name] [."authentication-method"] |@csv' -r
If you want additional details to be included, then you would modify the jq portion of the CLI command accordingly.
You can see the fields available here: https://sc1.checkpoint.com/documents/latest/APIs/index.html#cli/show-users~v1.9%20
Also, if you have lots of users, you may have to issue this command multiple times using the offset parameter to request the next set of results.