Please only use POST. Example usage on Linux/macOS: 

openssl rand 512 | openssl ts -query -data - -cert -sha512 | curl -s -S --data-binary @- https://rfc3161.ai.moda -o - -v | openssl ts -reply -text -in /dev/stdin

You can see the list of servers used at:
https://rfc3161.ai.moda/servers.json

We recommend using https://rfc3161.ai.moda (instead of any specific server URL), as this load balancer will automatically pick the fastest and most suitable timestamping server for your application.