Place GameObject on a plane via script

I'm working on a game with eyewear (e.g. Google Cardboard) and hence the player can't place the virtual object on the plane via touching the screen. I will utilize gestures to detect when the person intents to position the object.

Sadly, I couldn't figure out how to place the object on the plane with code in a script, e.g. the planeFinderBehaviour.PerformHitTest(...) Method seems to be not accessible. What is the recommended way to do this?

Thank you, I appreciate the support.