Line 13 can just be copied and pasted into your terminal, and switch out the argument $1 with the group.
#!/bin/sh
if [ -z = 1 ]; then
echo "[error] failed to supply name of user or group to backup\n"
echo " USAGE:"
echo " ./backup-repos.github.sh gnome"
else
curl -s https://api.github.com/orgs/$1/repos?per_page=200 | jq -r '.[].clone_url' | xargs -n 1 git clone
fi