In your WordPress Dashboard go to the Plugins section. Then, you need to click on the Add New option there.

On this page, there’s a search box on the top right side. There, you must type the keyword ‘menukaart’ and click enter to search this plugin.
In just a few moments, you can see the search results. So, you can also find the ‘WordPress Restaurant Menu Plugin – Menukaart’ plugin here. On this plugin, click on the Install Now button for installing it on your dashboard.