Thanks for reaching out and welcome to Netlify’s Support Forums!
I’m showing that you already have the domain assigned to a site here:
If you instead want to use that domain on your other site (which is on the same account), you’ll need to first remove the domain from the jackymao site, and then assign it to the jackymaocom site.
You can follow our Netlify docs for assigning a custom domain here:
Thank you so much! This is now solved following your links. I was oversight that site in the dash board as it only shows 4 sites by default, I now have seen all the sites.
Great job. Many thanks for providing this wondful netlify service as well as the outstanding support forum.