AX1800 DHCP domain setting

I don't know if this is the right place to ask, but I recently set up an WiFi 6 AX1800 Dual Band WAP WAX204 as my Internet router.

I have set up DHCP, and computers are being assigned IP addresses correctly.

DHCP normally has an option to set domain name, but I cannot find a place to set domain name in the router DHCP settings.

It is important to me that the computers have a default domain name, so I can set up DNS records in my DNS server to name the computers, so I can reach them by name. At the moment, I am having to type the full name (computername.my.domain) rather than just the computer name.

Is it possible to set the domain name via DHCP on this router, and, if so, how do I do it, please?