if you create a new virtual environment use:
conda create -n dmc python=3.6
conda activate dmc
and then
conda install -n dmc --yes --file requirements.txt
pip install lightgbm
pip install imblearn
pip install catboost
or if you install the packages in your base environment
conda install --yes --file requirements.txt
pip install lightgbm
pip install imblearn
pip install catboost