Hosting web site locally using reverse proxy: support for domain.com and www.domain.com

Describe the problem

Hi,
I have some little personal websites on a local machine (proxmox lxc) and I use netbird open source v. with reverse proxy to public online this websites.
All works very well but if I insert a rev. proxy www.mycustomdomain.com seems I’m not able to use also mycustomdomain.com
There is a way to have both or I need to insert another reverse proxy?