I don't have an emerald leaf, and as far as I know there's no instructions for finding them.
Also, for the linux version I have to run it by sticking it in the terminal and dealing with the terminal spamming "
[6813:6813:0813/005559.137417:ERROR:gl_utils.cc(316)] [.RendererMainThread-0x563864ecdde0] GL_INVALID_FRAMEBUFFER_OPERATION: Framebuffer is incomplete." Although the numbers keep changing.