usually buzzer have 2 pins pos and neg 1) weather giving 12V and GND it will turn on buzzer??I have tested 1 buzzer where i could give 12 v but it wont produce sound.
2. Usually datasheet says operating frequency of 2khz . Here i have created duty cycle of 2khz and turn on PWM pins high and low for 2khz of speed . These test done with speakers . Is it same case w.r.t buzzers??
3) what will be recommended buzzer my application. I am trying to use it for indication if any fault or sensor failure it has to give sound.https://startingelectronics.org/beginners/circuits/arduino-buzzer/weather this circuit more than enough