Use this cable to connect a CAN-bus enabled battery, not from Victron, to a Victron system. There are two types, A and B

VE.Can to CAN-bus BMS type B Cable for Batteries:

LG Chem Resu, AXIstorage, BMZ, Pylontech

Installation: The side labeled 'CAN-bus BMS' plugs into the battery. The other side, labeled 'VE.Can' must be plugged into the VE.Can port of the GX device.

For configuration, see the manual specific to the brand of battery you are using.