UI redesign question

ChirpStack Application Server
1

Hi!
Trying to redesign Application server ui to customize it for GPS tracking application.
Stuck on trying to remove side navigation bar (sideNav):

Screenshot from 2020-04-16 03-21-49
Screenshot from 2020-04-16 03-21-491781×901 347 KB

Commented this component in App.js file:

      {topNav}
      {/*sideNav*/}

But empty place still persists (red square on screenshot. Could someone advice how to remove it? Seems it is pretty easy question but I don’t have much experience with ReactJS.