Hey David,
your posting contains a bit little information.
Of course you can use a 220 V spindle on the Onefinity CNC machine. If it’s a 2.2 kW spindle, you will need the 80 mm spindle mount.
To operate a spindle, you need a VFD. Have you already bought one, and if so, which manufacturer, and which exact model is it?
The Onefinity Controller supports ModBus communication with VFDs via a serial connection. For this you have to select the appropriate VFD in the TOOLS page of the Onefinity Controller. You can also run a model that is not supported, by using a custom configuration.
The exact data for the configuration of the VFD and for the connection differ between VFD brands and models, you have to consult the manual of the VFD.
To connect the VFD to the Onefinity Controller you have to connect a shielded, twisted pair cable from pins 13 and 14 of the 25-pin I/O port of the Onefinity Controller to the RS485+ and RS485- pins of the VFD, and the shield to ground. See the instructions in your VFD manual.