Hi there and welcome.
It's definitely possible to show hostnames for clients, you can do this one of two ways:
-
Use PiHole as your DHCP server.
Do this if your DHCP server does not set hostnames for devices on the network
How do I use Pi-hole's built in DHCP server (and why would I want to)? -
Forward requests for your local domain to your DHCP server (usually your router)
Do this if you want to (or are unable to not) keep using your router as your DHCP server.
It is also possible to use /etc/hosts on the pihole to add static entries for local domains but this is bad practice for a network where the given IP address for a device may change.