Apple added exclusive features to the camera app in iPhone 11 which aren’t available for the previous iPhone models. Along with the new features, there are some interface updates as well to the camera app.
The filters option is no longer visible on the top right corner of the screen in camera app on iPhone 11. The creative controls menu that holds the filters option is now accessible from the little arrow icon at the top of the screen.
Tap the arrow icon, or swipe up on the viewfinder area to reveal the Creative Controls menu (above the shutter button). Tap the “Filters” icon at the right-most side of the menu to select and apply a filter to take a picture with.
That’s it. Have fun taking pictures on your iPhone 11 with them classy camera filters.