Open the frunk, remove the center trim panel behind the bin. As you stand looking at it, on the left is the HV battery coolant expansion tank and on the right is the HVAC/EV motor coolant expansion tank. Fluid should be at the MAX marks when cold (ambient temp 68F/20C or above - something comfortable and not freezing or excessively hot).
HV battery coolant level check
HVAC and EV motor coolant check
See the other thread for coolant specification type if you need to top it up.