You may have noticed that the controller ID user appears in plural form as users in the endpoint URLs. This is because [[yii\rest\UrlRule]] automatically pluralizes controller IDs when creating child URL rules. You may disable this behavior by setting [[yii\rest\UrlRule::pluralize]] to be false.
As the documentation says:
https://github.com/yiisoft/yii2/blob/master/docs/guide/rest-routing.md