A "not secure" message generally means that the SSL certificate is not active yet, that it is not installed for the correct domain, or that the website is still loading some elements over HTTP.
First check that the domain points to HOST.NC hosting. Once DNS is active, the SSL certificate can be generated from cPanel or activated by support.
If the certificate is active but the warning remains visible, it may be due to mixed content: images, scripts, or internal links still loaded with http:// instead of https://.