[monstantin]

componentDidMount() {

            let myHeaders = new Headers();
            myHeaders.append("authorization", "Token e3019694305911088a8d7add7f88b05af31cbe03");


            let myInit = {
                method: 'GET',
                headers: myHeaders
            };

            let myRequest = new Request('http://data.gov.spb.ru/api/v1/datasets/', myInit);

            fetch(myRequest).then(res => res.json())
            .then( (myBlob) => {
                console.log(myBlob);
            }).catch((e) => {
                console.log(e);
            })



        }

Failed to load http://data.gov.spb.ru/api/v1/datasets/: Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header contains multiple values '*, *', but only one is allowed. Origin 'http://localhost:3000' is therefore not allowed access. Have the server send the header with a valid value, or, if an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.