uses:
use filamentv\widgets\Breadcrumbs\Breadcrumbs;
$breadcrumbs ]); ?>uses:
use filamentv\widgets\LangSwitch\LangSwitch;
composer.phar require "filamentv/yii2-widget":"dev-master"
or add to composer.json into 'require' seaction
"filamentv/yii2-widget":"dev-master"