I can't update my address

I use ‘GET’ to update my IPv6 address. I set the parameter to IPv6 = auto. Although it shows that the update is successful, I check the result of dynv6.com and find that it has not been updated. What’s the matter? This is my request:
https://ipv6.dynv6.com/api/update/?token= ****************&zone= example.dynv6 .net&ipv6=auto