Install package apt-cacher-ng
Open up firewalls for port 3142

In /etc/apt-cacher-ng, add line:

Remap-devrep: file:devuan_mirrors /merged ; file:backends_devuan # Devuan Archives

Add empty file /etc/apt-cacher-ng/backends_devuan

create file /var/lib/apt-cacher-ng/devuan_mirrors with one line:

http://deb.devuan.org

symlink to /etc/apt-cacher-ng directory 2 files:

/var/lib/apt-cacher-ng/devuan.default
/var/lib/apt-cacher-ng/devuan_mirrors

Make sure /etc/apt-cacher-ng/security.conf has permissions and ownerships:

-rw-r----- 1 root apt-cacher-ng   401 May 30  2021 security.conf