I have a WordPress website and I want to add a custom endpoint that sends the metadata of the users.

Important:
The already API works only by calling it like this “domain-name.com/?rest_route=/wp/v2/users/”.
I know that for the API to work properly the standard solution for a custom endpoint is to change the permalink settings from plain to post.

Is there any solution without changing that setting?

The standard pre-built endpoints work fine when I call them like in the above example.