The controller
of yii\rest\urlRule
must be set. So you have to set this property when you add a controller. This project sloved it.
The preferred way to install this extension is through Composer .
composer require undefinedor/smart-rest
'urlManager' => [
'enablePrettyUrl' => true,
'showScriptName' => false,
'enableStrictParsing' => true,
'rules' => [
['class' => 'SmartRest\UrlRule'],
],
],