P0125 typically signals low coolant level, or a possible bad thermostat.
https://www.obd-codes.com/p0125
IF it is leaking from the radiator cap, you could replace it and see if that resolves your issue, though it is unlikely too. But, if it is leaking from that, that does need addressed anyways.
Check the coolant level when the vehicle is cold, and open the radiator cap. If you are low, add some coolant and try to keep from getting air in the system. Using a funnel like this is quite helpful for that.
https://www.amazon.com/EPAuto-Radiator- ... 6217&psc=1
Do you have a bluetooth code reader? You could hook it up and look at the coolant temps when the vehicle is warmed up. If the temp is around 175-180 or so for an OEM thermostat, it's likely the thermostat is bad. My coolant temperature runs at 176 most of the time.