How to secure your Netgear extender Setup_ And How to block devices from Netgear wifi extender. 
                     How to secure your Netgear extender Setup?
Do you fear that someone may enter the wifi network of 
your Netgear range extender? You've arrived to the right 
location if your response to the question was yes. Here, 
we’ll show you how to secure your 
Netgear wifi extender Setup. So, let’s get this party started.
Modify the Default Admin Information
1. Connect a power supply to your Netgear wifi extension.
2. Using a cable or wireless connection, join the extension to the router.
3. Get access to a computer or laptop after that.
4. Open a web browser, such as Safari, Edge, Chrome, Firefox, or another.
5. Please remember that your web browser must be up to date regardless of which one you 
use to change the default login admin information for your Netgear extender.
6. Look in the address bar.
7. Introducing mywifiext.local
8. Press the Enter key.
9. The Netgear Genie smart setup wizard will be displayed to you.
Read More:- How to block devices from Netgear wifi extender.