This page is testing the ability of a SRH (segment router header in IPv6) to reach you. If anything on the path between this server (located in France at OVH) and your browser blocks an ICMPv6 ECHO_REQUEST or UDP packet to the 'echo' port, then it will fail. This includes CPE firewalls as well as host firewalls.
Segment routing is described at: http://www.segment-routing.net/.
Your IP address is: 18.104.22.168. I am afraid that you reach this web site over IPv4 only... hence we cannot run the test.