I want to add the nameservers to use CDN on my website.
My Website hoster is 1&1 Ionos.
When I add the custom nameservers for CDN (Picture: http://prntscr.com/muwcr5)
I get this error:
Invalid name server settings
I called 1&1, they told me it has nothing to do with 1&1.
I also checked the nameserver on a third website https://www.denic.de/service/tools/nast/
They are also telling me, that the nameservers dosent work.
I hope someone can help me.