Where did you get the parameter from? I don't see it in the documentation.
https://www.traccar.org/api-reference/#path--users
It states the following:
userId Can only be used by admin or manager users type: query string
The real question would be, how can I retrieve a single user data by ID?
most APIs has the index route: users/ to retrieve a list of users, but also users/id to retrieve a user data by its id.
That's not for retrieving specific user. It's for retrieving list of users managed by specific user.
So, is there a way to retrieve specific user data by user ID? I would not like to get all users each time I search for it.
It's not possible at the moment. We usually just cache users.
When I try to use "/api/users?userId=1" to retrieve specific user, it shows an empty array. I have verified and the user from which Im authenticating to use the API does have Admin permissions. Any clues?