IKUpload: How to modify the GET request's header?

[devcloser]

From uploading-files-in-react docs

• I've created the auth endpoint (express-js)
• I've specificed the auth endpoint for authenticationEndpoint
• Image upload is working as expected

However, I have a concern that this is not considered secure as anyone could call the auth endpoint and get a token.

Then, I saw the reply here

    The endpoint is supposed to host on your backend. You can make it secure in a way that no unauthorised user can get token. Similar to how you might be protecting other resources on your application.

Originally posted by @imagekitio in https://github.com/imagekit-developer/imagekit-react/issues/50#issuecomment-945863423

So, I protected the auth endpoint, but I could not find a way to modify the authenticationEndpoint GET request's header to pass users Bearer Token along from the client-side.

Any advice, please?