It is a small icon on the center right edge of the screen that brings up on - screen buttons for navigation. (blog.the-ebook-reader.com)
Tap the Gear icon at the top right edge of the screen, and toggle off the Bixby key. (digitaltrends.com)
Control Center has also been shifted to a swipe down from the top right edge of the screen, with the notifications shade being located in the top left. (mobilesyrup.com)