D-Link DWA-645 User Manual page 28

Section  - Configuration
Enter the same security key or passphrase that is
on your router and click Connect.
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 on the wireless
router.
D-Link DWA-645 User Manual