How extends template

I downloaded pimcore, added my own controller, and added {% extends layout.html.twig %} in the view, but in the bar after breaking my controller, e.g. /admin/example instead of the pimcore template with my text from view, only the profiler at the bottom + black symfony bar is shown and that’s all. How can I use this main template in my controllers?

There is no “main template” you build all yourself but you can check out that example project it’s showing how to build product listing, some search, pages and so on!