USER_ERROR error message: header is not NLAuth scheme

I keep getting this error in postman “error code: USER_ERROR error message: header is not NLAuth scheme [ OAuth realm=“646033_Sxx%20”,oauth_consumer_key=“70xxxxxxx24b954f61bca134edc2e00eae81c9217eed4”,oauth_token=“06964c6bc0404a8c4a43fbd0d422xxxxxxx91c914456591ec0ed39a12de8dcd6d2b67aa”,oauth_signature_method=“HMAC-SHA1”,oauth_timestamp=“1551359964”,oauth_nonce=“bSPC9Uxt6d5B”,oauth_version=“1.0”,oauth_signature=“xxxxx%3D” ]”
Any help would be greatly appreciated.

Thank you.