Is it possible to have a share a singular interface on a vps for openstack neutron?

I'm having trouble with networking on linux. I am renting a vps with only one NIC, one ipv4 address, and a /64 range of ipv6 ones. I want to deploy openstack neutron to this vps, but openstack neutron is designed to be ran on machines with two NIC's, one for normal network access, and entirely dedicated to virtualized networking, like in my case, giving an openstack virtual machine a public ipv6 address. I want to create a virtual NIC, which can get it's own public ipv6 addresses, for the vm's, without losing functionality of the main NIC, and I also want the vm's to have ipv4 connectivity. I know this setup is possible, as the openstack docs say so, but they didnt' cover how to do so.

Docs: https://docs.openstack.org/kolla-ansible/latest/reference/networking/neutron.html#example-shared-interface

There is an overview of what you need to do here, but I don't understand how to turn this into a usable setup. In addition to that, it seems you would need to give vm's public ipv4 addresses, in order for them to have internet connectivity. I would need to create a NAT type network that routes through the main working interface, and then put the neutron interface partially behind that, in order for ipv4 connectivity to happen.

I've been searching around for a bit, so I know this exact setup is possible: https://jamielinux.com/docs/libvirt-networking-handbook/multiple-networks.html#example-2 (last updated in 2016, outdated)

But I haven't found an updated guide on how to do it.