What are the reasons for getting connection refused from API and the same is working fine when we hit it on the browser?

The message ‘Connection Refused’ has two main causes:

1. Nothing is listening on the IP:Port you are trying to connect to. (Kindly verify the IP and Port)
2. The port is blocked by a firewall.

Kindly confirm with the client if the IP is whitelisted in the firewall also confirm is there any port blockage or not. And ask for the telnet screenshot along with the port 6005.