Create an Orthographic Camera

You can define a new camera on a stage using UsdGeom.Camera. The Camera prim has a projection attribute that can be set to orthographic.

Omniverse Kit Commands

The CreatePrimWithDefaultXform command in Kit can create a Camera prim and you can optionally set camera attributes values during creation. You must use the attribute token names as the keys for the attributes dictionary. In Omniverse applications, you can explore the names by hovering over a property label in the Property Window and reading it from the tooltip.

import omni.kit.commands
from pxr import UsdGeom

omni.kit.commands.execute("CreatePrimWithDefaultXform",
   prim_type="Camera",
   prim_path="/World/MyOrthoCam",
   attributes={"projection": UsdGeom.Tokens.orthographic}
)

USD API

from pxr import Sdf, UsdGeom

camera_path = Sdf.Path("/World/MyOrthoCam")
usd_camera = UsdGeom.Camera.Define(stage, camera_path)
usd_camera.CreateProjectionAttr().Set(UsdGeom.Tokens.orthographic)