You are not connected to your extender's WiFi network. Please follow the steps to install your Extender
Step 1 : Open Setting > WiFi

Step 2 : Search for the network name "Extender-xxxx-2G" or Extender-xxxx-5G and connect it

ATTN: It's an open network so it shows up unsecured, you just need to connect to it.

Step 3 : Go back to the browser(Safari,Google,Firefox) tab and following: 192.168.10.1 or http://ax3000.online
192.168.10.1
Step 4 : Then follow the instructions