3.3V Pro Mini with RobotDyn Data Logger

Beginner’s question:

In trying to get my 3.3V Pro mini to talk to my RobotDyn data logger I notice that the Pro mini has no IORef pin (needed by the data logger). Does this mean I cannot use the Pro mini with this data logger? (I gather the 3.3V is too low?) (Not even sure I have given enough information…)