For an offline tool, there's yt-dlp which is already in your package manager, has 97k stars and supports 1800+ video sites [1].

    yt-dlp https://www.facebook.com/reel/554986104203104

1: https://github.com/yt-dlp/yt-dlp/blob/master/supportedsites....

I browse facebook using m.facebook.com in chrome on my Samsung. No interest in installing the app. If I press and hold on a playing video, I get the option to download an mp4. No extra site or software needed

Thankyou, I was looking for something like this the other day. Ended up screen recording. I'll check this out when I'm not at work.