Fortnite at 4: 3 black edges normal?

Ma
3

After some YouTube tutorials I have set my Fortnite settings 4: 3. But there were black edges on the side and not a drawn picture. Is that normal?

Ch

You have to play it in windowed mode. No plan like that was with me

Ma

But then me 4: 3 is not displayed

Ch

Vllt change resolution