Can we trigger backend code from server via external rest tool from agent ai studio

Summary:

Can we trigger backend code deployed on server via external rest tool from agent ai studio? As the code can be triggered from postman tool similarly can't we trigger it from agent using external REST tool, which has option of post method.

I have tried this scenario but seems to be errored. If some one tried this scenario and if its working let me know. I am getting the below error when tried.
I have just mentioned the content-Type as header and auth as none.

{ "responseStatus": 400, "response": { "type": "vb://network/unknownHost", "title": "Unknown Host", "detail": "Server <SERVER_NAME> Name or service not known is not found when a search if performed in the name servers.", "status": 400 }}