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


def create_perspective_camera(prim_path: str="/World/MyPerspCam"):
    """Create a perspective camera

    Args:
        prim_path (str, optional): The prim path where the camera should be created. Defaults to "/World/MyPerspCam".
    """

    omni.kit.commands.execute("CreatePrimWithDefaultXform",
       prim_type="Camera",
       prim_path=prim_path,
       attributes={
           "projection": UsdGeom.Tokens.perspective,
           "focalLength": 35,
           "horizontalAperture": 20.955,
           "verticalAperture": 15.2908,
           "clippingRange": (0.1, 100000)
       }
    )


#############    
# Full Usage
#############
import omni.usd


# Create a perspective camera at /World/MyPerspCam
path = "/World/MyPerspCam"
create_perspective_camera(path)

# Check that the camera was created
stage = omni.usd.get_context().get_stage()
prim = stage.GetPrimAtPath(path)
assert prim.IsValid() == True
assert prim.GetTypeName() == "Camera"
projection = prim.GetAttribute("projection").Get()
assert projection == UsdGeom.Tokens.perspective