F0 code means that the Split Air Conditioning is low in refrigerant gas.
If your split air conditioning is low in refrigerant gas, you must only allow a F-gas qualified engineer to attend to the problem. By law, only a qualified F-gas engineer can handle refrigerant gas in Europe.
The engineer will assess for any leakages or other faults and provide you with a service which will probably include a refrigerant top-up.