Is it possible to customize the HTML of the synology login page?

Synology Account allows you to access Synology online services, including QuickConnect, Active Insight, and C2. Synology Active Insight · My Synology NAS cannot boot... · DDNS · BeeStation

You can customize the appearance of the DSM login screen by choosing from a variety of templates, changing the background image, or adding a logo.

DSM and certain applications have separate login web portals. You can customize the login styles of the login screen by selecting from a variety of templates.

You can configure the login style, customize ports, and set up a domain name for your DSM in this tab. Go to Control Panel > Login Portal > DSM.

Enter your QuickConnect ID to access your Synology operating system. QuickConnect ID can include only English letters, numbers, and dashes (-).

I was wondering if there is an area that I would be able to edit the HTML/CSS of the synology login page or if that's not possible is it possible.

To log in to Synology DSM, connect via browser using NAS IP or server name, then enter your username and password on the login screen.

... the main Synology DSM login portal. In order to create login portals that also have a unique FQDN or URL you can definitely utilize the Synology ...