Create Configuration File

docker run -it --rm \
  -v $(pwd)/data:/data \
  -e SYNAPSE_SERVER_NAME=example.com \
  -e SYNAPSE_REPORT_STATS=no \
  matrixdotorg/synapse:latest generate

You can call the folder where the configuration files are stored in as you like. In my case I simply call it data

After you have generated the files you need to make sure that you change the ownership again to your user and group with UID=1000 and GID=1000. Normally it is set by default to 991. In our docker compose file we set it to 1000 and hence we need to adjust this. We choose 1000 since it is than easier for you as user to have the right permissions to create and access files regarding your synapse instance.