Request header was not present in the Access-Control-Allow-Headers list

Question

In my API, I have the following code:

public class CustomOAuthProvider : OAuthAuthorizationServerProvider
{

    public override Task MatchEndpoint(OAuthMatc         


        

Answer 1

No need to remove MatchEndPoint

Instead of adding array element just add Comma-Separated value as first array element in Access-Control-Allow-Headers

Instead of

 context.OwinContext.Response.Headers.Add("Access-Control-Allow-Headers", 
                new[] { 
                    "access-control-allow-origin", 
                    "accept", 
                    "x-api-applicationid", 
                    "content-type", 
                    "authorization" 
                });

use

context.OwinContext.Response.Headers.Add("Access-Control-Allow-Headers", 
    new[] { 
        "access-control-allow-origin,accept,x-api-applicationid,content-type,authorization" 
    });