Here is what you should do if you want to avoid adding Debian contrib as a repo in your /etc/apt/sources.list file:
sudo apt install build-essential debconf-2.0 debhelper dh-autoreconf wget libcap2-bin
wget http://ftp.us.debian.org/debian/pool/contrib/libd/libdvd-pkg/libdvd-pkg_1.4.2-1-1_all.deb
sudo dpkg -i libdvd-pkg_1.4.2-1-1_all.deb
For more info, see: https://packages.debian.org/buster/libdvd-pkg