You can respond to Duo mobile Push requests from the iOS lock screen or banner notification starting with Duo mobile version 3.8. The actions presented to you when you respond to the notification depend on your organization's Duo policy settings, such as whether or not you can approve the login request without PIN or biometric verification.

On Apple devices that support 3D Touch, performing a firm longpress on the Duo mobile notification from the lock screen reveals the "Approve" or "Deny" actions. Tap an action and supply your passcode or biometric verification (face or fingerprint) to complete the action.

On devices that do not feature 3D Touch, swipe left on the lock screen Duo mobile notification to reveal additional actions.

When your screen is unlocked, long-press or swipe down on the Duo mobile banner notification received to reveal the authentication actions.