Hi @abhi1788 , welcome to the community, and thanks for your question.
I will presume that you are using {{domainname}}
in the request URL. The ENOTFOUND error indicates that the system couldn’t do a DNS lookup, which sounds like Postman is sending that string as-is, and not finding your variable to replace the literal string with your intended server string.
Are you building this variable dynamically? Or is it an environment or collection variable? Can you give us a little more information?
Cheers,
Ian