When soldered directly on the two pins from the video...
But the 3rd pin also need to be soldered I've discovered later, because once the buzzer triggers (on low voltage and it even triggers while flying because it (the buzzer) is 5V and not 3.7V no matter that it triggers successfully when the Tello battery is full at 4.2V).
So if only the two pins from my video are soldered once the buzzer triggers it takes battery power from Tello battery instead of its own and while flying the Tello drastically goes down because the buzzer is taking lots of the current power to beep and lots of on screen errors are going on (failed motor, imu problem, bla bla bla).
The only resolution of this problem is to solder also the BB- of the buzzer to the Tello motherboard ground. From then on no issues occurs
Question. Where is Tello Motherboard ground to solder BB-?