RemoteControlModule.cpp

// check the example in bool FRemoteControlModule::SetObjectProperties

bool FRemoteControlModule::SetPresetController(const FRCControllerReference& ControllerRef, IStructDeserializerBackend& Backend, ERCPayloadType InPayloadType, const TArray<uint8>& InPayload, ERCModifyOperation Operation)
{
  // Logic
  
  // Check the Interceptor, it shoudl be implmented in Remote Control and nDisplay, but you can for first Prof of concept go without  Interceptor
  // But keep this in mind for the future
  
  	// Build interception command
		FString PropertyPathString = TFieldPath<FProperty>(ObjectAccess.Property.Get()).ToString();
		FRCIContollersMetadata ControllersMetadata(ObjectAccess.Object->GetPathName(), PropertyPathString, ObjectAccess.PropertyPathInfo.ToString(), ToExternal(ObjectAccess.Access), ToExternal(InPayloadType), ToExternal(Operation), InPayload);
  		
  // Pass interception command data to all available interceptors
		bool bShouldIntercept = false;
		for (int32 InterceptorIdx = 0; InterceptorIdx < InterceptorsAmount; ++InterceptorIdx)
		{
			IRemoteControlInterceptionFeatureInterceptor* const Interceptor = static_cast<IRemoteControlInterceptionFeatureInterceptor*>(ModularFeatures.GetModularFeatureImplementation(InterceptorFeatureName, InterceptorIdx));
			if (Interceptor)
			{
				// Update response flag
				UE_LOG(LogRemoteControl, VeryVerbose, TEXT("Set Object Properties - Intercepted"));
				bShouldIntercept |= (Interceptor->SetPresetController(PropsMetadata) == ERCIResponse::Intercept);
			}
		}
  	// Don't process the RC message if any of interceptors returned ERCIResponse::Intercept
		if (bShouldIntercept)
		{
			return true;
		}
  
  // Other logic
  // And filany desirialize, you need to implment
  bSuccess = FStructDeserializer::Deserialize(MutableObjectReference.ContainerAdress, *ContainerType, Backend, Policies);
	
// And after set the property value it should call the controller to execute the behaviour
// URCControllerContainer::OnModifyPropertyValue
// which is calling the Controller->ExecuteBehaviours(); 
}

WebRemoteControl.cpp

// for testing you can use postman 
// https://learning.postman.com/docs/sending-requests/requests/

void FWebRemoteControlModule::RegisterRoutes()
{
  // routers before
  	RegisterRoute({
		TEXT("Set a controller value on a preset."),
		FHttpPath(TEXT("/remote/preset/:preset/controller/:controller")),
		EHttpServerRequestVerbs::VERB_PUT,
		FRequestHandlerDelegate::CreateRaw(this, &FWebRemoteControlModule::HandlePresetSetControllerRoute)
		});

	RegisterRoute({
		TEXT("Get a controller value on a preset."),
		FHttpPath(TEXT("/remote/preset/:preset/controller/:controller")),
		EHttpServerRequestVerbs::VERB_GET,
		FRequestHandlerDelegate::CreateRaw(this, &FWebRemoteControlModule::HandlePresetGetControllerRoute)
		});

  // routers after
}

bool FWebRemoteControlModule::HandlePresetSetControllerRoute(const FHttpServerRequest& Request, const FHttpResultCallback& OnComplete)
{
  TUniquePtr<FHttpServerResponse> Response = WebRemoteControlInternalUtils::CreateHttpResponse();

	if (!WebRemoteControlInternalUtils::ValidateContentType(Request, TEXT("application/json"), OnComplete))
	{
		return true;
	}

	FRCPresetSetPropertyRequest SetPropertyRequest;
	if (!WebRemoteControlInternalUtils::DeserializeRequest(Request, &OnComplete, SetPropertyRequest))
	{
		return true;
	}

	FResolvePresetFieldArgs Args;
	Args.PresetName = Request.PathParams.FindChecked(TEXT("preset"));
	Args.ControllerName = Request.PathParams.FindChecked(TEXT("controllername"));

	URemoteControlPreset* Preset = WebRemoteControl::GetPreset(*Args.PresetName);
	if (Preset == nullptr)
	{
		Response->Code = EHttpServerResponseCodes::NotFound;
		WebRemoteControlInternalUtils::CreateUTF8ErrorMessage(TEXT("Unable to resolve the preset."), Response->Body);
		OnComplete(MoveTemp(Response));
		return true;
	}

	URCController* Controller = Preset->ControllerContainer->GetControllerByName(""); // It should be implmented, I can add it your you can add it
  
  
  // other logic , check HandlePresetSetPropertyRoute
  
  // Set the controller values
  IRemoteControlModule::Get().SetPresetController(ControllerRef, Backend, ERCPayloadType::Json, NewPayload, SetControllerRequest.Operation);
}