Turn Tap to Alexa On or Off. Use the device settings to enable Tap to Alexa on Echo devices with a screen. Say, “Go to settings,” or swipe down from the top of the screen and select Settings.; Select Accessibility.; Toggle Tap to Alexa on or off.
https://www.amazon.com/gp/help/customer/display.html?nodeId=GS2MNUFK2SBFJPCX