VR Expansion Plugin

Hi !
Very good job with plugin !
I successfully set up the movement of my character but i have trouble implementing the grip functions. I don’t understand segment from the documentation "All actors to be gripped currently MUST have a UPrimitiveComponent derived component as the ROOT component "
I first think i understand but i dont know how or where i can achieve with the actor i want to be grippable. When i want to add a component, i dont seem to find UPrimitiveComponent. I feel that i am missing something very simple here but i ve been stucked
for almost two days now lol