Youtube app iPhone - no home button, search etc.

When watching content on YouTube, the bottom bar with the account field, search, home, etc. disappears. Is it normal that I can't go back to the YouTube home page? The "back" gesture does not work (as in the case of other applications).

This is my first iPhone, I don't know if I don't understand something, is it normal? I have to use YT through a browser - then everything is ok.