Kim calculator problem

I am trying to run this small example of using OpenKim with ASE:

I am using a WSL with Ubuntu version “20.04.2 LTS (Focal Fossa)”.

I installed anaconda and then followed the instructions to install ase, kimpy and open kim models:
-conda install -c conda-forge kimpy openkim-models
-conda install -c conda-forge kimpy
-conda install -c conda-forge ase

I then run the code in the example, but when running:

calc = KIM(“ex_model_Ar_P_Morse_07C”)

I get: TypeError: ‘kimpy.collections.Collections’ object is not subscriptable

Is there a problem with my installation?

Thanks for your time.