ziopimpi

I solved the problem, the docker configuration was wrong. Here there's the right one. The configuration file is not necessary anymore with this simple configuration.
docker run -d --name='Rec' --net='bridge' --privileged=true -e TZ="Europe/Berlin" -e HOST_OS="Unraid" -e HOST_CONTAINERNAME="Rec" -e 'OTR_PORT'='0' -l net.unraid.docker.managed=dockerman -p '8083:8083/tcp' -v '/mnt/user/software/OwnTracks/Storage/':'/store':'rw' -v '/mnt/user/software/OwnTracks/Logs/':'/log':'rw' 'owntracks/recorder'  
Also, on the mobile device all the HTTP request must be submitted to the /pub endpoint.