The network security key, also known as the Wi-Fi password, is required to connect a printer or other wireless device to a Wi-Fi network. Here are some ways to find the network security key for your printer:

• Check the router: The network security key can be found on the router provided by your Internet Service Provider (ISP). Look for the password underneath or next to the Wireless Network Name or SSID. It might be labeled as Wireless Security Key/Password, Wi-Fi Password, Network Password, or Network Key.

• Check the router admin pages: The network security key can be found in the router admin pages. Access the router admin pages and look for the Wi-Fi password or security key.

• Reset the printer: If you have changed the Wi-Fi network name or password, you need to reconnect your printer to the network using the new login credentials. Reset your printer back to Network Defaults and then run the Wireless Setup Wizard to connect. Both can be accessed from the front panel or computer. If no front panel for configuration, you must use your Printer USB cable to connect. You can also try the WPS method if your router/printer supports this only if the Wizard or Printer USB cable is not available.

If none of these methods work, you can contact the printer manufacturers customer support for further assistance.