1991 Toyota Camry where to connect Buzzer for headlight

I want to connect buzzer ,so when my car's headlight is on & when i open door i will hear BEEP

i want to connect buzzer's +ve with headlight +ve
and Buzzer's -ve to Door's sensor

Please help to find cable & cable color so i can install buzzer to save my battery
Or if u have any idea PL Let me know

Thanks in advance
From brother hood