I've got the self hosted Docker standalone up and running. Now I was looking for the ingestion key, but there is no ingestion settings on the settings page. Now I've come to find this is only available for SigNoz cloud, and there is no key for a self hosted install., you just have to expose the otel collector ports 4317 and 4318. But how do I secure them? I have some servers I want to monitor, and this is over the internet.