[ 'request' => [ // !!! insert a secret key in the following (if it is empty) - this is required by cookie validation 'cookieValidationKey' => env('BACKEND_COOKIE_VALIDATION_KEY') ], 'urlManager' => [ 'enablePrettyUrl' => env('backend_enable_pretty_url', true), 'showScriptName' => false, ], ], ]; return $config;