Lnk2019/lnk2001

Hello,
I am trying to do a simple “Trigger” for a PointLight, this is my first C++ Code, but it doesnt compile (Error LNK2019/LNK2001) . Anyone know a solution?

Trigger.cpp
// Fill out your copyright notice in the Description page of Project Settings.

#include "Trigger.h"
#include "Components/PointLightComponent.h"


// Sets default values
ATrigger::ATrigger()
{
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;
	PointLight = CreateDefaultSubobject<UPointLightComponent>("Lighti");

}

// Called when the game starts or when spawned
void ATrigger::BeginPlay()
{
	Super::BeginPlay();
	PointLight->bVisible = true;

}

// Called every frame
void ATrigger::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

Trigger.h
// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "Components/PointLightComponent.h"
#include "Trigger.generated.h"

UCLASS()
class FORESTCP_API ATrigger : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	ATrigger();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;

	UPROPERTY(VisibleAnywhere)
		UPointLightComponent* PointLight;
	
	UFUNCTION()
		void ToggleLight();
	
};