Get and convert key
curl -fsSL https://minfba.de.dariah.eu/minfba_public.asc | sudo gpg -o /usr/share/keyrings/minfba.gpg --dearmor
Put in /etc/apt/sources.list.d/minfba.list or alike:
deb [arch=all signed-by=/usr/share/keyrings/minfba.gpg] https://minfba.de.dariah.eu/nexus/repository/minfba-apt-releases/ any main
deb [arch=all signed-by=/usr/share/keyrings/minfba.gpg] https://minfba.de.dariah.eu/nexus/repository/minfba-apt-testing/ any main