Can not connect with my Netgear Extender

After a technician had to fix some connection issue with my NBN and I reset my internet router with Optus I can no longer connect with my Netgear Extender. I've followed the guidance assistance and no matter how many times I did a factory reset it won't connect. It has found my router name and it shows up when I look under networks. It even shows that I'm connected but as soon as I open a browser or email it says no internet connection. I've been trying over two days now and don't know where else to turn to for help as my technical support has expired.

Thank you in advance for anyone who understands and can help me out.