Hello,
how can i use another dns to get the ip from? for example if i want to update with the ip from google.de how can i do this ? On No-ip its easy- i put the dns on target and it gets the ip from . But here i cant find anything .

We will go ahead and implement this functionality with a release date of 8/1/2017 based on your feedback.

BTW, the CNAME record can do the same in that it will simply resolve to the same IP as the DNS on target. You can use that for the next few days if you like.