D-Link AC1750 User Manual page 115

Section 5 - Connecting to a Wireless Network
5. Enter the same security key or passphrase (Wi-Fi password) that is on
your router and click Connect. You can also connect by pushing the
WPS button on the router.
It may take 20-30 seconds to connect to the wireless network. If the
connection fails, please verify that the security settings are correct. The
key or passphrase must be exactly the same as the one on the wireless
router.
D-Link DIR-869 User Manual 111