Using dynv6 on Speedport Hybrid Pro

Hello

I am pretty new to this so please forgive my noobish questions.
For a few hours I tried to set up the DynDns of my Telekom Router.

I used VPN previously on my FritzBox but only with the internal service.

Unfortunately i cannot get it to work.
I attached a picture of the stuff i have to fill out …
What’s the user name?
For username and password i followed the instructions under myzones.
for url i used https://ipv4.dynv6.com/api/update?ipv4=auto&token=$mytokenunderaccount$
no success.

what am i doing wrong?
I read that the speedport might have issues with ipv6 so i want to try 4 first …

Thanks a lot for your help!