Open Stack

Hey everyone.
So, I have developed openstack, wrote installers and fixed parts in the raw phytonutrients.. but... 
so I am , for fun and refreshing my memory, building an openstack deployment by hand, the hood old fashioned way.
I have a few servers and I get everything working perfectly EXCEPT neutron ovs with dvr integration.
I am using Ubuntu focal with ussuri release. When I deploy neutron i get the agents to show up and register with UP.
The neutron-openvswitch-agent crashes with physical network floating to br-public not found. 
I am wondering how in need to configure the bridge in order to make this work. I have a empty interface (internet facing) which I added to br-public but where do I define the floating network name?

Yes it’s stupid but I been banging my head against the wall:)

Thanks already for help and sorry to anyone else for the dumb question:)
//Florian