You can try using inspect element and see if the links to ths video files are available that way.

Have you tried using JDownloader? Copy paste the URL to it, and see if it can scan and find the video. Not sure if that would work, but there's a good chance.

If it doesn't work, try yt-dlp.

this is iffy, but you can use the inspector and try to find which of the files is the video you want, then download those manually. Less iffy, use obs-studio and record the videos like how we used to do music in cassettes (in real time).

if its ok could you link that file here? i've never seen such example so can't tell but i doubt they have strong (or any) drm