Display temp on second (aux batterys)

I have a second smart shunt connected to my starter batteries. It displays on the VRM dashboard with the voltage, current, name etc. no probs.
But it doesn’t show the temperature. I have the temperature sensor connected correctly and it does show this on the cerbo GX. But how do I get it to display in the VRM dashboard?
I’m told you can’t customise the dashboard at all so can someone from victron please, please make it work?