Hi @kouohhashi, as far as I know the summarisation scripts have been migrated to the seq2seq examples here: transformers/examples/seq2seq at master · huggingface/transformers · GitHub 9
There you can find BART, T5, and Pegasus, although I suggest starting with Pegasus since it produces decent summaries and is relatively light at ~500M params.
Note that the URL you link to is a different library to transformers: if you have questions about that library I suggest you open an issue in their repo / forum