307 Coolant Antifreeze depletion problem

Greetings to everyone... I have a 2004 307 Xt automatic gasoline LPG vehicle with a model of 240 thousand km. It constantly decreases water. I have to constantly monitor it ... All radiator maintenance, water pump timing set change, channel checks were done, gaskets were checked in general.. But my problem has not been solved... If anyone has knowledge about the subject, if you help me, I would say God bless you... Thank you

Hello, first of all, if your vehicle has been checked well and no water leak has been detected, there may be many reasons for this, except for leaks.