Oh, the game has instructions in this minigame. I added it after the first gameplay of Tiger J. It says: “(Hold down the left mouse button until you inhale the exact amount of air; release to exhale)”
You need to hold down the left mouse button until the white circle colides with the gray ring. In that moment, the ring changes to green, and you must release the left mouse button. There is a bar you need to fill (5 times doing it right). If you hold too much the button, the ring changes the color to red, and lost part of the progression bar.