@Annis 

Your network security key is your Wi-Fi network's password. As long as the Wi-Fi password for your network is being entered correctly (it is case sensitive), your laptop should connect when prompted.

If your Archer AX55 is using the default Wi-Fi password, you can find it printed on the label beneath the router. However, if the Wi-Fi password was customized during setup, you would need to use that password instead.