how to add subdomain for another account?

[tpu01yzx]

I have a domain example.com in account A. I can add a subdomain foo.example.com in account A too. Now I create another account B. I want to add domain foo.example.com in account B. However it failed with the following message:

Zone addition failed. Contact support (OV/foo.example.com)

How can it be solved ?

[cholzhauer]

Well, did you contact support?

[tpu01yzx]

Well, did you contact support?

How to contact support ? send a mail to some email address for help ?

[cholzhauer]

There is probably a better one, but ipv6@he.net is where I would start

[passport123]

How to contact support ? send a mail to some email address for help ?

On the FreeDNS page ( https://dns.he.net/ ) there's an email address for DNS support at the bottom of the page.