Fail to request access token from Auth0

I follow the test instruction to request a token from auth0 with jQUERY.

But I got the error message: Access to XMLHttpRequest at ‘’ from origin ‘http://localhost:3000’ has been blocked by CORS policy: Request header field access-control-allow-origin is not allowed by Access-Control-Allow-Headers in preflight response.

My application setting:

Please help me, I am struggling to request a token from Auth0.

Hello @zhujiajun62 welcome to the community!

Do you mind sharing the documentation you are working with?

What happens if you attempt to obtain a token using the same credentials using cURL?

Let us know!

Hi, tyf,
Thanks for the reply.
Here is my test code to request the token.

submitPost = (event) => {
    var settings = {
      "async": true,
      "crossDomain": true,
      "url": "",
      "method": "POST",
      "headers": {
        "content-type": "application/json",
        "Access-Control-Allow-Origin": "http://localhost:3000/"
      "data": "{\"client_id\":\"wRxxxxxxxxxxxxxxxxCG\",\"client_secret\":\"j4_xxxxxxxxxxWkCokt-dmrDlbwCxxxxxxxUUvLt_sO28W-ZP\",\"audience\":\"boardgameforum\",\"grant_type\":\"client_credentials\"}"

    $.ajax(settings).done(function (response) {

With your suggestion, I edit the curl and send it, out but the result I got is “invalid JSON”.

If you need more information, please let me know.

1 Like

No problem, happy to help where I can!

I’m not seeing anything that stands out in your code aside from the extra header "Access-Control-Allow-Origin": "http://localhost:3000/" - What happens if you remove that?

Do you mind trying the curl that from our article on Getting Access Tokens? I’m just trying to rule out any issues with obtaining a token in and of itself - CORS can sometimes be a red herring of sorts.

Keep us posted!

Hi, tyf,

Thank you for your reply. It works after removing the headers.
But I have another question, right now, I have the token in respons[“access_token”], and I want to do another ajax and add the token to the header. However, I assign it to a var but it is a local var. Can you advise how to pass this token to another ajax request?

Thank you very much.

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