From RobotinoWiki

Import key file

wget -qO - | sudo apt-key add -

Ubuntu 16.04 Xenial (image version 3.x)

sudo su
echo "deb xenial main" > /etc/apt/sources.list.d/openrobotino.list

Ubuntu 18.04 Bionic (image version 4.x)

sudo su
echo "deb bionic main" > /etc/apt/sources.list.d/openrobotino.list

Install single package

If you downloaded a single package you need to install all its dependencies manually. This can be done with the following command

gdebi my_package_1.0.deb