testing - not able to create IPv6 network on Mac

For testing purposes I tried to create IPv6 network from my Mac. I followed this tutorial: https://developer.apple.com/library/archive/documentation/NetworkingInternetWeb/Conceptual/NetworkingOverview/UnderstandingandPreparingfortheIPv6Transition/UnderstandingandPreparingfortheIPv6Transition.html

Except one thing. Instead of Thunderbolt Ethernet I used only Ethernet. WiFi was successfully created and I am able to use it.

However it seems, that the created WiFi is still not IPv6. I ran this test: http://ipv6-test.com and in results it says Not supported under IPv6 connectivity

What is the problem? Why is my network still IPv4? How can I create proper IPv6 network?