D-Link AC1200 User Manual page 26

Section 3 - Configuration
Enter a Wireless Network Name (SSID), then click Next to continue.
Choose the best security level supported by your wireless clients. Click Next to
continue.
Unless you chose None in the previous step, enter a security password. Clients must
enter this password to connect to your wireless network. You will be prompted to
select a password for both your 2.4 GHz and 5 GHz networks. Click Next to continue.
D-Link DWR-118 User Manual 22