D-Link DIR-860L User Manual page 38

Section 4 - Security
If you selected Automatically, the wizard will generate a pre-shared key
(password). The password will be the same for both the 2.4GHz and 5GHz
bands.
Click Next.
You will now see a summary window that displays your settings. Write down
the password and use it to access your wireless networks.
Click Save to save your settings.
D-Link DIR-860L User Manual 34