I've been asked to create a custom map for a client, similar to this one here. I've taken a look at the JS, and I really like how it was done but I can't seem to find anwhere they would've defined the custom background image. Furthermore, I can't find clear documentation on something like this.
To be clear, my client would like all of the same functionality but the background would of course be different.
Could someone point me in the direction of how this would be done with Google Maps' API or even how they did it?
Thanks so much!