Under the Manager MongoDB Users article in the Ops Manager documentation we have this bit:

SEE ALSO

To create one user with the Ops Manager API, see Create a User.

And:

SEE ALSO

To edit one user with the Ops Manager API, see Update a User.

And:

SEE ALSO

To create one user with the Ops Manager API, see /reference/api/delete-one-user.

All these reference are to the API documentation section that describes management of the Ops Manager users, not the MongoDB users. Thus these references are outside of the context of the article.

If we are to point users to the API documentation, we should be saying MongoDB users can be managed via the Automation Configuration endpoint ( auth.usersWanted field).