root@b1:~# sudo add-apt-repository cloud-archive:rocky --yes
...
root@b1:~# sudo apt update
...
root@b1:~# sudo apt install python3-neutron python3-neutron-fwaas neutron-l3-agent --yes
...
root@b1:~# dpkg -l | grep -E 'python-neutron |python3-neutron |neutron-l3-agent'
ii  neutron-l3-agent               2:13.0.2-0ubuntu3.1~cloud0         all          Neutron is a virtual network service for Openstack - l3 agent                                                           
ii  python3-neutron                2:13.0.2-0ubuntu3.1~cloud0         all          Neutron is a virtual network service for Openstack - Python library                                 
root@b1:~# sudo apt install neutron-l3-agent --yes
Reading package lists... Done
Building dependency tree       
Reading state information... Done
neutron-l3-agent is already the newest version (2:13.0.2-0ubuntu3.1~cloud0).
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
root@b1:~# dpkg -l | grep -E 'python-neutron |python3-neutron |neutron-l3-agent'
ii  neutron-l3-agent               2:13.0.2-0ubuntu3.1~cloud0         all          Neutron is a virtual network service for Openstack - l3 agent
ii  python3-neutron                2:13.0.2-0ubuntu3.1~cloud0         all          Neutron is a virtual network service for Openstack - Python library