Search Box not showing in the mobile view

Good day to you support-team, My site is: https://kreismedienzentrum.de/ The problem I am encountering is that the search box in the main navigation doesnt show up in the mobile version of the site. Is there any way to make this possible? I know there are some tricks to do that, but I would prefer to use a native way of the theme. I am not a coder so any help is appreciated. I looked through the supportforums but it seems that people only want to remove the box.