7 You must create the /etc/apt/sources.list.d/pgdg.list file and add the line: deb http://apt.postgresql.org/pub/repos/apt/ focal-pgdg main Then run: wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add - Finally, run: sudo apt-get update && sudo apt-get install pgadmin4