I found little to no information about setting up virtual hosts for this device so I made this guide.
For port 80/443
To start with. We need to add a new virtual host in web station.
Choose name-based here you have to add the domain or sub-domain that we want to use.
Choose the document root for our website. It needs to be in the web folder.
For the back-end, I choose Apache and PHP 5.6.
Next, we need to open the DNS manager for our domain.
Add a new CNAME record. This record will point the domain to our own domain or subdomain for which we will be using the Synology-s external access domain example.synology.me
In my case, it will be for the subdomain TEST
CNAME test gnat.synology.me
but this would work for the base domain too if we replace test with a star *
CNAME * gnat.synology.me
Save, And when we load the desired site test.tnorbert.com it redirects us to the Virtual Host.