Where does the sound come from this board? As the question says, i can't figure out where the sound comes from on this board that i bought, nothing on the manuals and can't see any speaker on the board... It is a "RFID Proximity Entry Door Secure Lock Access Control System"

Thanks.
That looks like a piezo buzzer, the component that had the sticker on it. It's likely louder now, with the sticker removed.