yii2 advanced app - Connecting Frontend to backend when login -

i have code in yii2 advanced template, want make link when log in frontend connecting in backend , when logout backend frontend,how can make that? , comon/config/main.php file

<?php return [ 'vendorpath' => dirname(dirname(__dir__)) . '/vendor', 'components' => [     'cache' => [         'class' => 'yii\caching\filecache',     ],      'urlmanager' => [     //'class' => 'yii\web\urlmanager',     'enableprettyurl' => false,     'showscriptname' => true,     'baseurl' => '/backend/web',     ],             'urlmanagerfrontend' => [     'class' => 'yii\web\urlmanager',     'baseurl' => '/frontend/web',     'enableprettyurl' => false,     'showscriptname' => true,     ] ], 

];

and sitecontroller in frontend

<?php namespace frontend\controllers;  use yii; use common\models\loginform; use frontend\models\passwordresetrequestform; use frontend\models\resetpasswordform; use frontend\models\signupform; use frontend\models\contactform; use yii\base\invalidparamexception; use yii\web\badrequesthttpexception; use yii\web\controller; use yii\filters\verbfilter; use yii\filters\accesscontrol; use yii\helpers\url; use backend;  /**   * site controller    */ class sitecontroller extends controller {    /**    * @inheritdoc     */ public function behaviors() {     return [         'access' => [             'class' => accesscontrol::classname(),             'only' => ['logout', 'signup'],             'rules' => [                 [                     'actions' => ['signup'],                     'allow' => true,                     'roles' => ['?'],                 ],                 [                     'actions' => ['logout'],                     'allow' => true,                     'roles' => ['@'],                 ],             ],         ],         'verbs' => [             'class' => verbfilter::classname(),             'actions' => [                 'logout' => ['post'],             ],         ],     ]; }  /**  * @inheritdoc  */ public function actions() {     return [         'error' => [             'class' => 'yii\web\erroraction',         ],         'captcha' => [             'class' => 'yii\captcha\captchaaction',             'fixedverifycode' => yii_env_test ? 'testme' : null,         ],     ]; }  /**  * displays homepage.  *  * @return mixed  */ public function actionindex() {     return $this->render('index'); }  /**  * logs in user.  *  * @return mixed  */ public function actionlogin() {     if (!\yii::$app->user->isguest) {         return $this->gohome();     }      $model = new loginform();     if ($model->load(yii::$app->request->post()) && $model->login()) {         return $this->goback();     } else {         return $this->render('login', [             'model' => $model,         ]);     } }  /**  * logs out current user.  *  * @return mixed  */ public function actionlogout() {     yii::$app->user->logout();      return $this->gohome(); }  /**  * displays contact page.  *  * @return mixed  */ public function actioncontact() {     $model = new contactform();     if ($model->load(yii::$app->request->post()) && $model->validate()) {         if ($model->sendemail(yii::$app->params['adminemail'])) {             yii::$app->session->setflash('success', 'thank contacting us. respond possible.');         } else {             yii::$app->session->setflash('error', 'there error sending email.');         }          return $this->refresh();     } else {         return $this->render('contact', [             'model' => $model,         ]);     } }  /**  * displays page.  *  * @return mixed  */ public function actionabout() {     return $this->render('about'); }  /**  * signs user up.  *  * @return mixed  */ public function actionsignup() {     $model = new signupform();     if ($model->load(yii::$app->request->post())) {         if ($user = $model->signup()) {             if (yii::$app->getuser()->login($user)) {                 return $this->gohome();             }         }     }      return $this->render('signup', [         'model' => $model,     ]); }  /**  * requests password reset.  *  * @return mixed  */ public function actionrequestpasswordreset() {     $model = new passwordresetrequestform();     if ($model->load(yii::$app->request->post()) && $model->validate()) {         if ($model->sendemail()) {             yii::$app->session->setflash('success', 'check email further instructions.');              return $this->gohome();         } else {             yii::$app->session->setflash('error', 'sorry, unable reset password email provided.');         }     }      return $this->render('requestpasswordresettoken', [         'model' => $model,     ]); }  /**  * resets password.  *  * @param string $token  * @return mixed  * @throws badrequesthttpexception  */ public function actionresetpassword($token) {     try {         $model = new resetpasswordform($token);     } catch (invalidparamexception $e) {         throw new badrequesthttpexception($e->getmessage());     }      if ($model->load(yii::$app->request->post()) && $model->validate() && $model->resetpassword()) {         yii::$app->session->setflash('success', 'new password saved.');          return $this->gohome();     }      return $this->render('resetpassword', [         'model' => $model,     ]); }  /*public function goback($defaulturl = null) {     if(is_null($defaulturl)) {         $defaulturl = yii::$app->request->baseurl; // ganti dibagian ini ndu     }      return yii::$app->getresponse()->redirect(yii::$app->getuser()->getreturnurl($defaulturl)); }*/  } 

and same sitecontroller in backend