Lubuntu 18.04 (Bionic Beaver) was released April 27, 2018 and will reach End of Life on Friday, April 30, 2021. This means that after that date there will be no further security updates or bugfixes released. We highly recommend that you re-install with 20.04 as soon as possible if you are still running 18.04.
After April 30th, the only supported releases of Lubuntu will be 20.04 (until April 2023), 20.10 (until July 2021), and 21.04 (until January 2022). All other releases of Lubuntu will be considered unsupported, and will no longer receive any further updates (or support) from the Lubuntu team.
You can find instructions on how to install Lubuntu in our manual.
Note, due to the extensive changes required for the shift in desktop environments, the Lubuntu team does not support upgrading from 18.04 or below to any greater release. Doing so will result in a broken system. If you are on 18.04 or below and would like to upgrade, please do a fresh install. The installation image can be obtained from our downloads page.
For further details please refer to our forum post.