Lean touch one object

Hello, everybody!
I am a novice at Unity and with friends we create an augmented reality scene with vuforia. In this scene I would like that when the user touches a chest, its animation changes so that it opens.
To do this, I downloaded the asset "lean touch" that I used several times.
And for this example, it works... but it works on the entire screen. That is, if I press anywhere on the screen the chest opens. I would like this effect to apply only when the user touches the chest only.
Do you have a solution for me?

Thank you in advance!

 

Hi marie,
Can you please tell me how have you done it? I'm looking for the same.