I want to connect a custom domain hosted by Internex, an Austrian domain registrar and hosting provider, to an Odoo website on sh V19:

• The www subdomain points to Odoo via CNAME.
• The root domain should permanently redirect to the HTTPS www address.

Internex informed me that they do not support an HTTPS redirect for the root domain with a valid SSL certificate.

Is there a reliable solution without using Cloudflare or another paid third-party service?