Bonjour,
Je viens de tester avec la même vidéo et chez moi, ça marche pas non plus :
[youtube] Extracting URL: https://www.youtube.com/watch?v=8upK-MfOxW0
[youtube] 8upK-MfOxW0: Downloading webpage
WARNING: [youtube] unable to extract initial player response; please report this issue on https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using yt-dlp -U
[youtube] 8upK-MfOxW0: Downloading android player API JSON
[youtube] 8upK-MfOxW0: Downloading iframe API JS
[youtube] 8upK-MfOxW0: Downloading player f130aa11
[youtube] 8upK-MfOxW0: Downloading web player API JSON
WARNING: [youtube] unable to extract yt initial data; please report this issue on https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using yt-dlp -U
[youtube] 8upK-MfOxW0: Downloading initial data API JSON
[info] 8upK-MfOxW0: Downloading 1 format(s): 303+251
[dashsegments] Total fragments: 10
[download] Destination: Welcome Debian 11 [8upK-MfOxW0].f303.webm
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (1/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (2/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (3/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (4/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (5/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (6/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (7/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (8/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (9/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (10/10)...
[download] Got error: HTTP Error 403: Forbidden. Giving up after 10 retries
ERROR: fragment 1 not found, unable to continue
[dashsegments] Total fragments: 2
[download] Destination: Welcome Debian 11 [8upK-MfOxW0].f251.webm
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (1/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (2/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (3/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (4/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (5/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (6/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (7/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (8/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (9/10)...
[download] Got error: HTTP Error 403: Forbidden. Retrying fragment 1 (10/10)...
[download] Got error: HTTP Error 403: Forbidden. Giving up after 10 retries
ERROR: fragment 1 not found, unable to continue
Ça, par contre, ça donne un résultat chez moi :
Available version: stable@2023.09.24, Current version: stable@2023.03.04
ERROR: As yt-dlp has been installed via apt, you should use that to update. If you're on a stable release, also check backports.
Et, effectivement, la version en backports (Debian 12) est plus récente et j’ai pu télécharger la vidéo sans problème avec.
Par contre, je ne sais pas du tout quelle version tu as, ni comment tu l’as l’installée, ni sur quelle version de Debian tu es, je ne peux donc pas te donner plus d’indications.