megatron-core was not found
python punctuation_capitalization_train_evaluate.py
gives me
[NeMo W 2023-10-05 22:24:59 nemo_logging:393] megatron-core was not found. Please see the NeMo README for installation instructions: https://github.com/NVIDIA/NeMo#megatron-gpt.
I can't understand how can I install megatron-gpt?
There is an instruction how to install Apex. But I already have Apex.
Or maybe I need to install Transformer Engine?

Thanks in advance.