Changing default LoadBalancer External-IP

I'm using Traefik on a k3s cluster with a single node (running in IPv6 mode).

By default the LoadBalancer service ("traefik") which serves ports 80 and 443 binds to one of the ip addresses available on my eth1 interface.

I'd like it to bind to a different address on the same interface.
I'm not sure if this is achieved by Traefik configuration or k3s, I'd be happy to get any pointers.