debian-backports.sh

#!/bin/bash

apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 7638D0442B90D010
apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 04EE7237B7D453EC

rm -f /etc/apt/sources.list.d/buster-backports.list
echo "deb http://deb.debian.org/debian buster-backports main" | tee -a /etc/apt/sources.list.d/buster-backports.list

apt-get update

echo apt-cache -t buster-backports search foo
echo apt-get -t buster-backports install foo