Hi @Dgyjj, let me see if I can help out here.
I have translated your question to English as this is an International forum, please post any replies in English and it will be easier for me and other users to assist you.
Fullscreen mode can be enabled in the app code of some apps, such as Youtube, Netflix and various gaming apps. However, it is not possible to hide the navigation bar using the UI settings of the device. Depending on the app or content, the proper fullscreen mode will be activated automatically.
There are, however, third-party apps available on Google Play that will offer fullscreen mode for all apps and content.
I hope that answered your question!
