Client API with Webroot

[misc_bb 7]

I'm building a simple client app to retrieve data from a Webroot API. I tested authentication in Postman and everything works just fine. I'm trying to replicate what I have in Postman in Delphi using the REST client components but I encounter an error which I don't really know what exactly is causing it but maybe you guys can help me out. 

 

RESTClient1.BaseURL := 'https://unityapi.webrootcloudav.com/';

  RESTClient1.Accept := 'application/json';
  RESTClient1.Params.AddItem('Content-Type','application/x-www-form-urlencoded',TRESTRequestParameterkind.pkHTTPHEADER, [TRESTRequestParameterOption.poDoNotEncode]);
  RESTClient1.Params.AddItem('Authorization', 'Basic ' + sAuthorization, TRESTRequestParameterkind.pkHTTPHEADER, [TRESTRequestParameterOption.poDoNotEncode]);
  RESTRequest1.Resource := 'auth/token';

  RESTRequest1.Params.AddItem('username', sUsername, TRESTRequestParameterKind.pkREQUESTBODY);
  RESTRequest1.Params.AddItem('password', sPassword, TRESTRequestParameterKind.pkREQUESTBODY);
  RESTRequest1.Params.AddItem('grant_type', 'password', TRESTRequestParameterKind.pkREQUESTBODY);
  RESTRequest1.Params.AddItem('scope', '*', TRESTRequestParameterKind.pkREQUESTBODY);

  RESTRequest1.Method := TRESTRequestMethod.rmPOST;
  RESTRequest1.Execute;
  memo1.Lines.Add(RESTResponse1.Content);

 

For the sAuthorization variable - it's already a base64 encoded value as specified in the Webroot guidelines: https://unityapi.webrootcloudav.com/Docs/en/APIDoc/PasswordAuthentication

Also sUsername, sPassword they already have corresponding values. 

This request is for authentication which will return an access token. But it seems the grant_type value is causing the error which i cannot figure out.

 

When I run my code, it always return this error: 

{"statusCode":400,"requestId":"54bf21a8-cee9-4bef-ac5d-2704dd9f23c1","error":"unsupported_grant_type","error_description":"Invalid grant type has been sent.","AdditionalInformation":{}}

 

Maybe you have the same experienced and was able to resolved, please let me know. Thank you.