Issue with installing causalml package python

I am trying to install the package causalml in Jupyter using pip, and I get the following error:

ERROR: Command errored out with exit status 1:
 command: /opt/conda/bin/python3.6 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-h3qf0rqq/causalml_92ba9279cfbd4f77ac1f50f04998c187/setup.py'"'"'; __file__='"'"'/tmp/pip-install-h3qf0rqq/causalml_92ba9279cfbd4f77ac1f50f04998c187/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-m0xr_f2v
     cwd: /tmp/pip-install-h3qf0rqq/causalml_92ba9279cfbd4f77ac1f50f04998c187/
Complete output (20 lines):
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/tmp/pip-install-h3qf0rqq/causalml_92ba9279cfbd4f77ac1f50f04998c187/setup.py", line 56, in <module>
    ext_modules=cythonize(extensions),
  File "/opt/conda/lib/python3.6/site-packages/Cython/Build/Dependencies.py", line 962, in cythonize
    ctx = c_options.create_context()
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/Main.py", line 597, in create_context
    self.cplus, self.language_level, options=self)
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/Main.py", line 80, in __init__
    from . import Builtin, CythonScope
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/CythonScope.py", line 5, in <module>
    from .UtilityCode import CythonUtilityCode
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/UtilityCode.py", line 3, in <module>
    from .TreeFragment import parse_from_strings, StringParseContext
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/TreeFragment.py", line 17, in <module>
    from .Visitor import VisitorTransform
  File "Cython/Compiler/Visitor.py", line 17, in init Cython.Compiler.Visitor
  File "/opt/conda/lib/python3.6/site-packages/Cython/Compiler/ExprNodes.py", line 46, in <module>
    from .Pythran import (to_pythran, is_pythran_supported_type, is_pythran_supported_operation_type,
ImportError: cannot import name 'pythran_is_numpy_func_supported'
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

In another forum, I read that this is a cython issue, I have uninstalled and reinstalled it, and it did not work out. I am working with Python 3.6.10, and here are the versions of the dependent packages on my system.

setuptools= 50.3.0
pip=20.3
numpy=1.18.5
scipy=1.4.1
matplotlib
pandas=1.1.2
scikit-learn=0.23.2
statsmodels=0.12.0
seaborn
Cython=0.29.21
xgboost
pydotplus
tqdm
shap
dill
lightgbm
pygam
packaging
keras
tensorflow=2.3.0

I checked the dependency requirements, and I believe all the above packages are acceptable for installing causalml. I also tried cloning the git repo and installing it, and I got the same error. Your feedback and suggestion are greatly appreciated.