Hi @asibarra98
You need to launch a SimulationApp instance before importing those modules.
Cite from SimulationApp docstring:
Omniverse loads various plugins at runtime which cannot be imported unless the Toolkit is already running. Thus, it is necessary to launch the Toolkit first from your python application and then import everything else.
If you check the examples the modules are imported after kit execution, such as:
...
kit = SimulationApp(launch_config=CONFIG)
from omni.isaac.core.utils.extensions import enable_extension
from omni.isaac.core.utils.stage import set_stage_up_axis, add_reference_to_stage
import omni
from pxr import UsdGeom, Gf
...