Print it in the given orientation without support. Solid 100% infill for the lever part on the bottom recommended for sturdiness, you could (like I did) for example set 15 solid bottom layers at 0.2mm layer height. Or maybe simply print everything with 100% infill.
There are two tiny built in support triangles which you need to remove with a cutter knife, see pictures.
The author marked this model as their own original creation.