Header error when creating new API Poller (SAM)

We are trying to setup a new API poller but when we enter the send request for our URL we are getting the following error. How do we go about resolving this?

Response status : NotAcceptable
Response status code : 406
Response time (ms) : 63
message : Invalid Accept header sent with request. Must be text/plain;version=0.0.4;charset=utf-8