luckily yes I will change the instructions on the website as well.
As Debian maintainers decided to not include poldi-ctrl anymore, you can use gpg-connect-agent instead.
sudo sh -c 'gpg-connect-agent "/datafile /etc/poldi/localdb/keys/D00600012401020000000000xxxxxxxx" "SCD READKEY --advanced OPENPGP.3" /bye'
This should do the job. Please remember to change the ‘xxxxxxx’ above with your card information. It is may needed to disconnect and connect the stick again at first.