How to Convert 'data.ilearner' Model to 'model.pkl' in Azure ML?

Question

I created a pipeline in Azure ML that trains a model using Boosted Decision Tree Regression. From my understanding, the model is saved as data.ilearner.

However, I am unable to convert this model into a model.pkl format that can be loaded using joblib.

Questions:

1. How can I create a model.pkl file in Azure ML for a Boosted Decision Tree Regression model?
2. How can I convert data.ilearner to model.pkl?

I attempted to use the following Python script to load and convert the model:

import lightgbm as lgb
import joblib

# Load the LightGBM model
model = lgb.Booster(model_file="data.ilearner")

# Save as a Pickle file
joblib.dump(model, "model.pkl") 

But when running the script, I get the following error:

% python3 convert_to_model_pkl.py 
[LightGBM] [Fatal] Unknown model format or submodel type in model file data.ilearner
Traceback (most recent call last):
  File "/Users/tomasz.olchawa/ng/ml/convert_to_model_pkl.py", line 5, in <module>
    model = lgb.Booster(model_file="data.ilearner")
  File "/Users/tomasz.olchawa/ng/ml/myenv/lib/python3.13/site-packages/lightgbm/basic.py", line 3697, in __init__
    _safe_call(
    ~~~~~~~~~~^
        _LIB.LGBM_BoosterCreateFromModelfile(
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<3 lines>...
        )
        ^
    )
    ^
  File "/Users/../ng/ml/myenv/lib/python3.13/site-packages/lightgbm/basic.py", line 313, in _safe_call
    raise LightGBMError(_LIB.LGBM_GetLastError().decode("utf-8"))
lightgbm.basic.LightGBMError: Unknown model format or submodel type in model file data.ilearner