RBAC setup?

[srakl]

in my modules i have this

 'admin' => [
                    'class' => \Da\User\Controller\AdminController::class,
                    //'administratorPermissionName' => 'admin',
                    'as access' => [
                        'class' => yii\filters\AccessControl::class,
                        'rules' => [
                            //['allow' => true, 'actions' => ['index','switch-identity']],
                            ['allow' => true, 'permissions' => ['admin']],
                        ],
                    ],
                ],

but my when i got to https://blabla.com/backend/web/user/admin/index/ i'm getting a yii\web\ForbiddenHttpException error

how do you set this up? what am i missing?

is there any full tutorial to set up RBAC?