Public void ToMenu() Why isn't this function in EventTrigger?

Question

C++ / C#

Help me please!
I have the following in the Achievments scene code:

public void ToMenu()
{
SceneManager.LoadScene(0);
}
private void Update()
{

}
}

I created a button in the Canvas, then added an EventTrigger to the components and I can't add a function to make the camera return to the main scene. What can be done?