Hi @gizmo,
Thanks for reaching out and welcome to Netlify’s Support Forums!
I do see that you’ve configured the DNS for offer.gizmo3dprinters.com.au to have the CNAME Record point to offergizmo3dprinters.netlify.app. However, the subdomain hasn’t been added to the site here. Please assign the subdomain to the site.
Also note that the apex domain (gizmo3dprinters.com.au) and subdomain (www.gizmo3dprinters.com.au) have not had their DNS configured for External DNS. You can follow the linked Netlify doc to help with configuring the DNS, or you can follow option 1 of our Support Guide here.