How to using VR hand to control an actor's rotation?

Hello,folks. I used to ask a question about using the mouse to control the actor’s rotation.How to use mouse drag to control actor's rotation? - Programming & Scripting - Unreal Engine Forums.
Now a similar question comes to me, that is using HTC Vive to control the actor’s rotation. For example, I move Right_MotionController to left while pressing the grip button, and the actor turns to the left by a certain angle. Here are my code which didn’t work

282041-capture2.png

I type a . after the link I list before.So try How to use mouse drag to control actor's rotation? - Programming & Scripting - Unreal Engine Forums

I thought I did myself.

Here my solution.Pic1 is my VRpawn, Pic2 is the actor which be rotating.
And if you got another solution, welcome to share yours.