Add the following lines to your /etc/apt/sources.list:
deb http://download.telldus.com/debian/ stable main
or
deb https://s3.eu-central-1.amazonaws.com/download.telldus.com unstable main
wget http://download.telldus.com/debian/telldus-public.key
sudo apt-key add telldus-public.key
apt update
sudo apt-get install telldus-core libtelldus-core-dev
pip install tellcore-py
sudo systemctl enable /home/bridge/nexabridge/nexabridge.service
sudo service nexabridge start