After following these exact steps it now finally worked (except the hdmi output but that could be a Problem with our App)
Install Balenaos in Docker Container on PI 4:
Documentation:
- Ubuntu Server for Pi4 as Base OS (because it´s 64 bit)
https://github.com/TheRemote/Ubuntu-Server-raspi4-unofficial/releases
login: ubuntu pw:ubuntu
- Install the Docker
https://phoenixnap.com/kb/docker-on-raspberry-pi
https://github.com/balena-os/balenaos-in-container
https://hub.docker.com/r/resin/resinos/tags?page=1&name=raspberrypi3
sudo apt-get update && sudo apt-get upgrade
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh
sudo apt-get install git
git clone https://github.com/balena-os/balenaos-in-container.git
sudo docker pull resin/resinos:2.47.1_rev1.dev-raspberrypi4-64
cd balenaos-in-container
sudo ./balenaos-in-container.sh --image resin/resinos:2.47.1_rev1.dev-raspberrypi4-64 --id test -c “/tmp/config.json”
Thank you all for helping me out here!