etc/frontend/di.xml
<?xml version="1.0"?>
<!--
/**
* Copyright © 2018 Stämpfli AG. All rights reserved.
* @author avs@integer-net.de
*/
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\Framework\View\Page\Config">
<plugin name="staempfli_seo_page_config" type="Staempfli\Seo\Plugin\PageConfigPlugin" />
</type>
<type name="Magento\Framework\App\Route\Config">
<plugin name="staempfli_seo_route_config" type="Staempfli\Seo\Plugin\RouteConfigPlugin" />
</type>
</config>