Step:
1. The parts we need in this project.
2. Some steps to make this circuit.
3. Test the buzzer, then add the led to test the indicator.
Components list
(1.) 12V Relay https://www.utsource.net/itm/p/1870494.html
(2.) Capacitor 25V 2200uf https://www.utsource.net/itm/p/9509010.html
(3.) Capacitor 25V 1000uf https://www.utsource.net/itm/p/9506441.html
(4.) Buzzer https://www.utsource.net/itm/p/8027891.html
(5.) Resistor 220 Ohm https://www.utsource.net/itm/p/6491244.html
More details, pls check the video on Youtube: