I tried it with a Russian YT video and it did not work:
Starting process...
Processing URL: https://www.youtube.com/watch?v=MtkgT6R2HtA
Error: Failed to get transcript:
Could not retrieve a transcript for the video https://www.youtube.com/watch?v=MtkgT6R2HtA! This is most likely caused by:
No transcripts were found for any of the requested language codes: ['en']
For this video (MtkgT6R2HtA) transcripts are available in the following languages:
(MANUALLY CREATED)
None
(GENERATED)
- ru ("Russian (auto-generated)")[TRANSLATABLE]
(TRANSLATION LANGUAGES)
- en ("English")
If you are sure that the described cause is not responsible for this error and that a transcript should be retrievable, please create an issue at https://github.com/jdepoix/youtube-transcript-api/issues. Please add which version of youtube_transcript_api you are using and provide the information needed to replicate the error. Also make sure that there are no open issues which already describe your problem!
--- End of summary ---