D-Link AC1750 User Manual page 112

Section 6 - Connecting to a Wireless Network
You will then be prompted to enter the network security key (Wi-Fi password)
for the wireless network. Enter the password into the box and click Next.
If you wish to use Wi-Fi Protected Setup (WPS) to connect to the router, you
can also press the WPS button on your router during this step to enable the
WPS function.
When you have established a successful connection to a wireless network, the
word Connected will appear next to the name of the network to which you
are connected to.
D-Link DIR-869 User Manual 108