Health check curl example

I am not understanding how this health check[1] script should work. From the commandline it works fine when I type a PING I get a PONG. But how do I do a curl to this 5001 port?

Tried something like this:

bash-5.0# curl http://localhost:5001/ curl: (56) Recv failure: Connection reset by peer

bash-5.0# curl http://localhost:5001/PING curl: (56) Recv failure: Connection reset by peer

[1] https://doc.dovecot.org/admin_manual/health_check/