Ultrasonic Sensor with Buzzer

So basically my project is an "ILLEGAL PARKING DETECTOR"

I'm using an Ultrasonic sensor with a buzzer. I want to make my buzzer sound whenever the ultrasonic detects the car for a 1-minute exposure in the ultrasonic sensor. Whenever the car moves or goes away under the 1-minute mark, the buzzer will not sound.

Ok.
Thanks for letting us know

(deleted)

Did you want help with something? What does your sketch do so far?

Is it something like this?

If there is no car present:
restart a timer and turn off the buzzer.

If the timer has reached 1 minute:
turn on the buzzer.