YOUR APT Repo

Overview of Packages

Import verification key

sudo wget -O /usr/share/keyrings/your-archive-keyring.gpg  http://apt.your-domain.de/keys/your-archive-keyring.gpg

Add this repository

/etc/apt/sources.list.d/your.sources (Use your distribution) 
Enabled: yes
Types: deb deb-src
URIs: http://apt.your-domain.de
Suites: focal
Components: main
Signed-By: /usr/share/keyrings/your-archive-keyring.gpg

Update your package list

sudo apt-get update