Stuck in the POST section of Web Requests module

I’m having trouble getting the flag to output after this command…
Curl -x post -d ‘{“search”:“flag”}’ -b ‘authenticatedcookiehere’ -H ‘content-type: application/json’ http://serverip:port/search.php…>
It either outputs use authenticated cookie!, or (5) something about the proxy cant post.
What am i doing wrong here? I’ve tried resetting the box and the target server ip and i cant get it. Been stuck for 2 days