origin 'null' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

[bhargavr445]

UI: React.js(axios)(http://ipaddress:3001)
Backend: Node.js.
Single-sign-on

I my app from UI I am trying to hit '/login' route in node.js and fetching login_url from serviceProvider method(sp.create_login_request_url) in line 2, after receiving login_url i am trying to redirect to the received URL(login_url) in line 5 then I am getting the below error.

Node.js- login endpoint

1. app.get("/login", function(req, res) {
2. sp.create_login_request_url(idp, {}, function(err, login_url, request_id) {

3. if (err != null)
   

4.   return res.send(500);
   

5. res.redirect(login_url);
   

6. });
7. });

Access to XMLHttpRequest at 'https://some.url/idp/SSO.saml2?SAMLRequest=someEncodedText' (redirected from 'https://dev-intcxsearch.dol.gov/login') from origin 'http://ipaddress:3001' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.