Try to start Grafana with this command:
docker run -d -p 3000:3000 \
-e "GF_INSTALL_PLUGINS=https://github.com/IoTOpen/grafana-datasource-lynx/archive/refs/tags/3.1.0.zip;iotopen-datasource" \
-e "GF_PLUGINS_ALLOW_LOADING_UNSIGNED_PLUGINS=iotopen-datasource" --name=Grafana grafana/grafana:latest
You'll probably have to remove your old container. The command you have probably installs an old version of the plugin. I'll fix that in the documentation today.