How do I select any particular network interface from multiple NICs in a VM to be added to the Backend Address Pool of a Load Balancer?

When configuring a Load Balancer by default only the primary/first network interface out of multiple NICs of the VM is showing in the backend pool configuration. 

How do I select any particular network interface from multiple NICs in a VM to be added to the Backend Address Pool of a Load Balancer? I don't see any option to select from the multiple NICs of a VM.



Thanks! Regards, Gautam