To install the GNU Taler Ubuntu packages, first ensure that you have
the right Ubuntu distribution. At this time, the packages are built for
Ubuntu 20.04 LTS (Focal Fossa).

.. FIXME: https://bugs.gnunet.org/view.php?id=7261

Note that as of 2022, GNU Taler uses PostgreSQL 13, which is not available
out-of-the-box for Ubuntu 20.04.  To install it, follow
`these instructions <https://computingforgeeks.com/how-to-install-postgresql-13-on-ubuntu/>`__.
After this is done, you can continue here.

.. This para is still not enough to resolve the FIXME, however.  Still TODO:
   - Verify 22.04 has PostgreSQL 13 OOTB.
   - Verify Taler packages install correctly on 22.04.
   - Update instructions to s/focal-fossa/jammy-jellyfish/ etc.

A typical ``/etc/apt/sources.list.d/taler.list`` file for this setup
would look like this:

.. code-block::

   deb https://deb.taler.net/apt/ubuntu/ focal-fossa main

The last line is crucial, as it adds the GNU Taler packages.

Next, you must import the Taler Systems SA public package signing key
into your keyring and update the package lists:

.. code-block:: console

   # wget -O - https://taler.net/taler-systems.gpg.key | apt-key add -
   # apt update

.. note::

   You may want to verify the correctness of the Taler Systems key out-of-band.

Now your system is ready to install the official GNU Taler binary packages
using apt.