Unity xt380 how to add ha for management ip address

We have Unity xt 380 for management is specified ip address, in the interfaces at the moment this ip is shown on SPARE A in Access mode. This port on spare B is connected to a switch in the same VLAN in Access mode. at the moment there is a problem with the physical connection for some reason on spare A. We completely lose control of the system. At the same time there is no way to configure any fault tolerance for management ip. How do we back up the management interface LACP, or stand by, or just specify an additional IP for Spare B.