The stl should load in the correct orientation for printing and requires no support. Since this will be under a fair bit of load I suggest a rigid nylon for best results. I have also used a lot of petg with no issues. I doubt PLA would last as long, but maybe it would be fine. Print solid or nearly solid with many walls thick. Keep cooling fan off for best bonding though you may need some cooling where it bridges. Try without any cooling first.
I made the first ones a few years ago and they are still doing their job after going through hot summers and sub zero winters. Haven't had one break yet.
The author marked this model as their own original creation.