You need to register for the community site. Registration link is here
Yes F9 customers can get the domain name, when you logged into the portal you should have been greeted with a button to click if you wanted the domain. Assuming you have selected this all you need to do now is go through the domain registration at this link and ensure you choose a .co.uk, .me.uk or .org.uk and you won't get charged for it.
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