What is the proper syntax of complex arguments in a UE4 javascript function call?

I’ve gotta be missing something. The answer is probably ridiculously easy and I’m just completely not seeing it.
Say, I’ve got the sample UE4 project that has a couple of chairs and a table and I’m utilizing the WebBrowser module. I BindUObject one of the chairs so I have access to it in javascript. On the javascript side, I want to simply rotate the chair. I have access to k2_SetActorRotation on the bound chair object, and the C++ function signature of this function is:

bool K2_SetActorRotation
FRotator NewRotation,
bool bTeleportPhysics

How the heck do I pass the Pitch, Yaw, and Roll of the FRotator in my javascript call? I’ve tried several different ways such as:

this.unreal(‘chair’, ‘k2_setactorrotation’, {pitch: 0, yaw: 180, roll: 0}, true);
this.unreal(‘chair’, k2_setactorrotation’, {NewRotation:{pitch: 0, yaw: 180, roll:0}, bTeleportPhysics: true});

but the rotation that comes through in UE4 is always 0,0,0. If I pass a simple value to, say, a custom function I put in the chair’s blueprint, I can get that value. But if it’s a struct (like the above FRotator) it’s always zero rotator. What is the proper syntax for passing this sort of data? Thanks in advance.