OAuth flow failed.Verify the configurations and try again. Error detail:invalid_request, Missing parameters: access_tokenIssue The Get OAUth token feature is throwing the error "OAuth flow failed. Verify the configurations and try again. Error detail:invalid_request, Missing parameters: access_token" Testing from POSTMAN is not throwing any error and getting the proper token.CauseAdd the log statements in the script include "OAuthUtil" and see the response gs.log("accessTokenResponse.getContentType()===>" +accessTokenResponse.getContentType());gs.log("accessTokenResponse.getBody()====>" +accessTokenResponse.getBody()); Results: 2019-07-12 12:14:45 Information accessTokenResponse.getContentType()===>null *** Script 2019-07-12 12:14:45 Information accessTokenResponse.getBody()====>{ "access_token" : "123123123123", "token_type" : "Bearer", "expires_in" : 86400 } Here we can see the Content-Type is null, which is throwing the error based on the IF condition in the "OAuthUtil".ResolutionComment out the below IF condition can fix the issue: //if (contentType && contentType.indexOf('application/json') != -1) { var tokenResponse = (new global.JSON()).decode(accessTokenResponse.getBody()); var paramMap = accessTokenResponse.getparameters(); for (param in tokenResponse) paramMap.put(param, tokenResponse[param].toString()); //} To permanently fix the issue you can extend this script include and overwrite this function with these lines commented out OR create a new script include called, for example, "OAuthUtilClient", copy-paste the code from script include "OAuthUtil" and comment out the lines.