You`re talking about a loopback interface (bridge) but in the example there is no Loopback
Sorry - I assumed you were using loopback interfaces in your existing IPv4 configuration.
Loopback interfaces aren't required, per-se - but it's best practice in a dynamic routing environment that every router have a loopback interface with a /32 assigned to it (IPv4) and a /128 assigned to it (in IPv6) - and to use the loopback IP as the router-id in all protocols, configurations, etc.
They're especially recommended as tunnel endpoint addresses, since the source IP might go away if it's bound to a physical interface and that interface goes down. A loopback interface will always be reachable so long as the router has at least one up-and-running ospf interface.
If you haven't been doing this, then that's why you don't have a loopback interface. Things will work without it, but it's not best practice.
In IPv6 routing, you don't even need public addresses on the router-to-router interfaces anyway, as OSPFv3 uses the link-local address as the next hop. If you have a routable address on the loopback interface, then the router will use that in all of its "correspondence" with the world - traceroute replies / icmp unreaqchable / ping source / etc.
