Issue with Adding Domain Aliases to 'roomen.netlify.app' - Domain Alias Owned by Another Account

I am trying to add the domains ‘roomen.r-e.kr’ and ‘www.roomen.r-e.kr’ to the site ‘roomen.netlify.app’. However, when I attempt to add a domain alias, I get the message:
“domain_aliases is owned by another account. Domain aliases are typically used to link additional vanity URLs to your site besides the primary domain.”

Why is this happening?
Even though the domain is set up with a CNAME pointing to ‘roomen.netlify.app’, it still doesn’t work.
Please check and confirm.
Let me know if you need further clarifications!

Hi @bassistjune,

Thanks for reaching out!

Could you add a TXT Record so we can verify ownership of the domain by following this Support Guide:

Once you’ve created the TXT Record and it’s propagated, please let us know and we’ll check to verify.