Black screen in camera app

I have an Iphone X and I can’t take any photos on various apps like snapchat, instagram, camera... everywhere. I see a black screen and my front camera turn on sometimes but back camera doesn’t work. And a flashlight doesn’t work either. I have the latest iphone updates and I restarted the phone several times, It didn’t help. Can I fix it? My phone is under warranty. Is it necessary to go to the apple service? Please help.