Question subdomain as Domain unregistered

[pcchirurg]

Server operating system version

Ubuntu 24.04.4 LTS

Plesk version and microupdate number

Plesk Obsidian 18.0.79 Update 5 Web Host Edition

I need to set up a subdomain as an unregistered domain on a server so that I can create a legal notice (Impressum) page for the hostname.
The problem is that I can only create a registered domain or a temporary domain generated by Plesk.
This applies whether I use "Add Domain" or "Add Subscription."
This remains the case even when I switch the interface to "Power User View" (for developers and web agencies).
I cannot find an option anywhere to create the subdomain as a domain (unregistered).
I had an old set of instructions from Plesk where this was possible.
What can I do?

 

[Sebahat.hadzhi]

@pcchirurg , is there a specific error you get? I am not entirely sure what should "unregistered domain" mean, but if I interpret that correct and you mean a domain that hasn't been actually registered with any Domain Registrar, the first thing that pops in my mind is that you might have "Prohibit creating domains that resolve to other servers" enabled in Tools & Settings > Prohibited Domain Names.