Greetings

trying to install postgres 13 on beowulf
the official instructions are using systemd ephemera

I included the repository (postgresql) as suggested:

deb http://deb.devuan.org/merged beowulf-backports main contrib non-free
deb-src http://deb.devuan.org/merged beowulf-backports main contrib non-free

deb http://apt.postgresql.org/pub/repos/apt/ buster-pgdg main
~

but - - - - when I use
# apt update
Hit:1 http://deb.devuan.org/merged beowulf InRelease
Hit:2 http://deb.devuan.org/merged beowulf-security InRelease
Hit:3 http://apt.postgresql.org/pub/repos/apt buster-pgdg InRelease
Ign:4 http://apt.postgresql.org/pub/repos/apt beowulf-pgdg InRelease
Hit:5 http://deb.devuan.org/merged beowulf-updates InRelease
Hit:6 http://deb.devuan.org/merged beowulf-backports InRelease
Err:7 http://apt.postgresql.org/pub/repos/apt beowulf-pgdg Release
404 Not Found [IP: 87.238.57.227 80]
Reading package lists... Done
E: The repository 'http://apt.postgresql.org/pub/repos/apt
beowulf-pgdg Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is
therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user
configuration details.

Somehow what I entered as 'Buster' become 'Beowulf' .

How can I install postgresql 13 on Beowulf?

TIA