Err? - Ch 7 - Verify the Local Configuration

It indeed does not exist by default least on ubuntu -- although it does exist on all Red Hat based platforms, such as RHEL, CentOS and Fedora. There is a man page on ubuntu for dhclient.releases but the file doesn't seem to be there, at least on 22.04. Maybe someone else knows the answer to this

The best method to view the DHCP client information in a NetworkManager environment is to have NetworkManager show us the information.
Step 1 find the active adaptor in your system with:
$ nmcli connection show -a
The output should be similar to:
Wired connection 1 8a96df6d-993f-407d-859a-62e08dc95441 ethernet enp3s0
Notice the connection NAME on this system is:
"Wired connection 1"

Now fetch the DHCP data:
$ nmcli connection show Wired\ connection\ 1 | grep "^DHCP4"
The output should be similar to:

DHCP4.OPTION[1]: dhcp_lease_time = 21600
DHCP4.OPTION[2]: dhcp_server_identifier = 192.168.0.1
DHCP4.OPTION[3]: domain_name = onapinglake.com
DHCP4.OPTION[4]: domain_name_servers = 192.168.0.1
DHCP4.OPTION[5]: expiry = 1677720069
DHCP4.OPTION[6]: ip_address = 192.168.0.216
DHCP4.OPTION[7]: next_server = 192.168.0.1
DHCP4.OPTION[8]: requested_broadcast_address = 1
DHCP4.OPTION[9]: requested_domain_name = 1
DHCP4.OPTION[10]: requested_domain_name_servers = 1
DHCP4.OPTION[11]: requested_domain_search = 1
DHCP4.OPTION[12]: requested_host_name = 1
DHCP4.OPTION[13]: requested_interface_mtu = 1
DHCP4.OPTION[14]: requested_ms_classless_static_routes = 1
DHCP4.OPTION[15]: requested_nis_domain = 1
DHCP4.OPTION[16]: requested_nis_servers = 1
DHCP4.OPTION[17]: requested_ntp_servers = 1
DHCP4.OPTION[18]: requested_rfc3442_classless_static_routes = 1
DHCP4.OPTION[19]: requested_root_path = 1
DHCP4.OPTION[20]: requested_routers = 1
DHCP4.OPTION[21]: requested_static_routes = 1
DHCP4.OPTION[22]: requested_subnet_mask = 1
DHCP4.OPTION[23]: requested_time_offset = 1
DHCP4.OPTION[24]: requested_wpad = 1
DHCP4.OPTION[25]: routers = 192.168.0.1
DHCP4.OPTION[26]: subnet_mask = 255.255.255.0

We can see the information passed to us by the dhcp server.