Which MultiPlus-II 12/3000 230 V is this?
This page covers MultiPlus-II 12/3000/120-32, 230 V AC: a 12 V battery connection, 3000 VA / 2400 W inverter at 25°C, 120 A charger and 32 A transfer switch. Check the exact column in Victron's specifications.
The 120 in the model number is charging current. It does not identify AC voltage. The single 120 V model and 2x120 V model retain separate entries. Switching this page to AWG changes the presentation, not the hardware.