How to find link to video file from URL

[Pavel_47]

Tried with multiple options trying to obtain output file with subtitles.
None of them worked.
Here is one case (I tried to convert vtt to srt; without converting it doesn't work either):

Output:
(arte_env) pavel@ALABAMA:~/arte_env$ yt-dlp --ignore-errors --add-metadata --write-info-json --write-description --write-annotations --write-thumbnail --xattrs --all-sub --write-sub --sub-format vtt --convert-subtitles srt --embed-sub -o "bbb.mp4" "www.arte.tv/fr/videos/092925-000-A/un-million-d-annees/"
WARNING: [generic] The url doesn't specify the protocol, trying with http
[ArteTV] 092925-000-A: Downloading JSON metadata
[ArteTV] 092925-000-A: Downloading m3u8 information
[ArteTV] 092925-000-A: Downloading m3u8 information
[info] 092925-000-A: Downloading 1 format(s): VO-STF-2232+VO-STF-program_audio_0-VO
[info] Writing video description to: bbb.description
[info] Writing video subtitles to: bbb.fr.vtt
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 1
[download] Destination: bbb.fr.vtt
[download] 100% of 7.40KiB in 00:00
[info] Writing video subtitles to: bbb.de.vtt
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 1
[download] Destination: bbb.de.vtt
[download] 100% of 6.98KiB in 00:00
[info] Downloading video thumbnail 0 ...
[info] Writing video thumbnail 0 to: bbb.jpg
[info] Writing video metadata as JSON to: bbb.info.json
WARNING: There are no annotations to write.
[SubtitlesConvertor] Converting subtitles
Deleting original file bbb.fr.vtt (pass -k to keep)
Deleting original file bbb.de.vtt (pass -k to keep)
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 199
[download] Destination: bbb.fVO-STF-2232.mp4
[download] 100% of 599.54MiB in 02:34
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 200
[download] Destination: bbb.fVO-STF-program_audio_0-VO.mp4
[download] 100% of 35.42MiB in 00:44
[Merger] Merging formats into "bbb.mp4"
Deleting original file bbb.fVO-STF-2232.mp4 (pass -k to keep)
Deleting original file bbb.fVO-STF-program_audio_0-VO.mp4 (pass -k to keep)
[EmbedSubtitle] Embedding subtitles in "bbb.mp4"
ERROR: file:bbb.fr.srt: Invalid data found when processing input
[Metadata] Adding metadata to "bbb.mp4"
[XAttrMetadata] Writing metadata to file's xattrs
(arte_env) pavel@ALABAMA:~/arte_env

Any comments ?
Thanks