title: Keycloak Get Users returns 403 forbidden
body: <p>I create token using <code>http://localhost:8080/auth/realms/{realm_name}/protocol/openid-connect/token endpoint</code>.</p>
  <p>grant_type=client_credentials<br />
  client-id: ------------<br />
  client-secret: 78296d38-cc82-4010-a817-65c283484e51</p>
  <p>Now I want to get users of realm. Then I send request to <code>http://localhost:8080/auth/admin/realms/{realm_name}/users?username=demo</code> endpoint with token.
  But I got <code>403 forbidden</code> response with <code>&quot;error&quot;: &quot;unknown_error&quot;</code>. How to solve it?</p>