The official site of Bigrats is flvcd.com, which only provides Windows version.
This project is the Linux version of Bigrats video downloader written in Golang with GUI by deploying GoQt, and uses avidemux to merge video segments. It will support MacOS very soon. This project has nothing to do with flvcd.com.
Install the extension from https://addons.mozilla.org/zh-CN/firefox/addon/flvcd-helper
This procedure is different for Debian and Ubuntu.
Add following line into /etc/apt/sources.list
deb http://ftp.kaist.ac.kr/debian-multimedia/ buster main
(replace buster with your Debian codename, you can get it by lsb_release -cs
)
(you can also install avidemux-qt to merge video segments manually)
Download bigrats-go installer from releases.
Now you can use it as if you were using the Windows version!
If you are interest in building bigrats-go from source code, please refer to: How to build bigrats-go from source on Debian/Ubuntu