manager-bundle/src/EventListener/BackendMenuListener.php
public function onBuild(MenuEvent $event): void
    {
        if (null === $this->managerPath || !$this->isAdminUser()) {
            return;
        }

        $categoryNode = $event->getTree()->getChild('system');

        if (null === $categoryNode) {
            return;
        }

        $item = $event->getFactory()->createItem(
            'contao_manager',
            [
                'label' => 'Contao Manager',
                'attributes' => [
                    'title' => 'Contao Manager',
                    'href' => '/'.$this->managerPath,
                    'class' => 'navigation contao_manager',
                ],
            ]
        );

        $categoryNode->addChild($item);
    }
public function onBuild(MenuEvent $event): void
    {
        if (null === $this->managerPath || !$this->isAdminUser()) {
            return;
        }

        $categoryNode = $event->getTree()->getChild('system');

        if (null === $categoryNode) {
            return;
        }

        $item = $event->getFactory()->createItem(
            'contao_manager',
            [
                'label' => 'Contao Manager',
                'attributes' => [
                    'title' => 'Contao Manager',
                    'href' => '/'.$this->managerPath,
                    'class' => 'navigation contao_manager',
                ],
            ]
        );

        $categoryNode->addChild($item);
    }
Adds a link to the Contao Manager in the back end navigation.