I have my custom domain which is http://iiicrusoe.io/ which is registered with Network Solutions.
I have set up an alias for my custom domain pointing to the nettlify.app subdomain but after a couple of days it is still showing the parked page from Network Solutions.
I’d suggest checking that you have configured the Netlify name servers at Network Solutions. If they’re still showing a parked page, that means we haven’t entered the equation yet!
Do you mean under my Domain Management page for my actual domain name click Options -> Set up Netlify DNS and put those DNS records in my DNS records under Network Solutions? I thought that was only if you were having Netlify manage the domain.
The name servers for https://iiicrusoe.io are not pointing to Netlify. You’ll need to point these to us at your registrar. If you click on the error in the UI, it will provide you with the information you need !