error on dimlinear

[treevine191]

i am trying to use the dimlinear

start = APoint(0,0)
end = APoint(600,-600)
acad.add_dimension(Dimension(start, end, APoint(-1000, -300), DimensionType.LINEAR))

but its says error adding dimension

`AttributeError Traceback (most recent call last)
File ~\Documents\Anaconda\AutoCAD-main\AutoCAD.py:196, in AutoCAD.add_dimension(self, dimension)
195 elif dimension.dimension_type == DimensionType.LINEAR:
--> 196 dimension_obj = self.modelspace.AddDimLinear(dimension.start_point.to_variant(), dimension.end_point.to_variant(), dimension.text_point.to_variant())
197 elif dimension.dimension_type == DimensionType.ANGULAR:

File ~\anaconda3\Lib\site-packages\win32com\client\dynamic.py:629, in CDispatch.getattr(self, attr)
628 # no where else to look.
--> 629 raise AttributeError(f"{self.username}.{attr}")

AttributeError: .AddDimLinear

During handling of the above exception, another exception occurred:

AutoCADError Traceback (most recent call last)
Cell In[15], line 3
1 start = APoint(0,0)
2 end = APoint(600,-600)
----> 3 acad.add_dimension(Dimension(start, end, APoint(-1000, -300), DimensionType.LINEAR))

File ~\Documents\Anaconda\AutoCAD-main\AutoCAD.py:205, in AutoCAD.add_dimension(self, dimension)
203 return dimension_obj
204 except Exception as e:
--> 205 raise AutoCADError(f"Error adding dimension: {e}")

AutoCADError: Error adding dimension: .AddDimLinear`

can you help me with this one sir?
thank you very much for this package by the way