D-Link AC750 User Manual page 20

Section 3 - Configuration
If the router detected or you selected Static, enter the IP and DNS
settings supplied by your ISP. Click Next to continue.
For both the 2.4 GHz and 5 GHz segments, create a Wi-Fi network name
(SSID) using up to 32 characters.
Create a Wi-Fi password (between 8-63 characters). Your wireless clients
will need to have this passphrase or key entered to be able to connect
to your wireless network.
Click Next to continue.
In order to secure your router, please enter a new password. Check the
Enable Graphical Authentication box to enable CAPTCHA authentication
for added security. Click Next to continue.
D-Link DIR-816L User Manual 15