The product page for that buzzer says "current consumption: 20 mA" These piezo buzzers can be corrected directly to a DC supply. There is no need for a current-limiting R (as for an LED).

The base unit houses an Arduino board which polls the buttons to see which is pressed first. The LED on the appropriate buzzer box is illuminated so the players know who got in first.

Inside the cool laser-cut box is an Arduino Uno and a 9V battery, plus a current-limiting resistor and the all-important buzzer. ... to build a project based on your 1D LED pong, Arduino-style ...

With each contact you make, the red LED lights up, the buzzer beeps and the seven-segment LED display counts up. After making contact ten times, the buzzer blares out an annoying sound — game over.

The Arduwire UNO is an innovative shield designed for the Arduino UNO development board. ... while a red LED and buzzer signal a problem such as an open circuit, short, or miswire.