c# NATS auth callout Authentication

I want to implement out callout authentication on NATS. I have created a console application that listens to the $SYS.REQ.USER.AUTH topic. Based on the received username and password, I generate a JWT token and allow the user to access their authorized topics. However, after generating the token, I encounter the following error:

Has anyone faced a similar issue? Thanks in advance.

7] 2025/03/12 18:47:28.318794 [ERR] 127.0.0.1:34882 - cid:32 - authentication error - User "alice" 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.318831 [TRC] 127.0.0.1:34882 - cid:32 - ->> [-ERR Authorization Violation] 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.318869 [DBG] 127.0.0.1:34882 - cid:32 - Client connection closed: Authentication Failure 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.318941 [WRN] Not an authorization request claim 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.318973 [TRC] ACCOUNT - <-> [DELSUB 28] 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.318990 [ERR] 127.0.0.1:34882 - cid:32 - authentication error - User "alice" 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.319038 [TRC] ACCOUNT - <<- [PUB $SYS.ACCOUNT.CLIENT.AUTH.ERR 763] 2025-03-12 21:47:28 [7] 2025/03/12 18:47:28.319047 [TRC] ACCOUNT - <<- MSG_PAYLOAD: ["{"type":"io.nats.server.advisory.v1.client_disconnect","id":"KOwQzxP6idqSC7QHOVpLD5","timestamp":"2025-03-12T18:47:28.318985439Z","server":{"name":"NAIKY3SN333SJMWKMJVCTK77YY5MFOHOVWZLIKMGXCQ4EHGUDJE3TMLQ","host":"0.0.0.0","id":"NAIKY3SN333SJMWKMJVCTK77YY5MFOHOVWZLIKMGXCQ4EHGUDJE3TMLQ","domain":"mainnode","ver":"2.10.26","jetstream":true,"flags":3,"seq":280,"time":"2025-03-12T18:47:28.319024442Z"},"client":{"start":"2025-03-12T18:47:28.313633709Z","host":"127.0.0.1","id":32,"acc":"AUTH","user":"alice","name":"NATS CLI Version 0.1.6","lang":"go","ver":"1.38.0","rtt":621000,"stop":"2025-03-12T18:47:28.318985439Z","kind":"Client","client_type":"nats"},"sent":{"msgs":0,"bytes":0},"received":{"msgs":0,"bytes":0},"reason":"Not an authorization request claim"}"]

 private static string CreateUserJwt(User user, AuthorizationRequest request){

 var issuerKey = "SAAH3RHRIFXZGSPDONXD3X2LK4LUSQSEPFXFIROLEH6C2UJBHHTVGX5KLI";
 var IssuerPublicKey = "ABC53VGEEBXCIWW4AJKLL2JMVPUUXXF74LCM3Q6AHLPWKH5JLDO7VCGQ";

 var keyPair = Nkeys.FromSeed(issuerKey);

 var jwtHeader = new
 {
     typ = "JWT",
     alg = "ed25519-nkey"
 };

 var natsData = new
 {
     type = "user",
     version = 2,
     pub = new
     {
         allow = new[] { "test.>" } 
     },
     sub = new
     {
         allow = new[] { "test.>" } 
     },
     data = -1,
     payload = -1
 };

 var jwtPayload = new
 {
     aud = request.Nats.ServerId.Id,
     jti = Guid.NewGuid().ToString().Replace("-", "").ToUpper(),
     iat = DateTimeOffset.UtcNow.ToUnixTimeSeconds(),
     iss = IssuerPublicKey,
     name = user.Username,
     sub = request.Nats.UserNKey,
     nats = natsData
 };

 string encodedHeader = Base64UrlEncode(JsonConvert.SerializeObject(jwtHeader));
 string encodedPayload = Base64UrlEncode(JsonConvert.SerializeObject(jwtPayload));

 // JWT Signing Input
 string signingInput = $"{encodedHeader}.{encodedPayload}";
 byte[] signingBytes = Encoding.UTF8.GetBytes(signingInput);

 byte[] signature = keyPair.Sign(signingBytes);
 string encodedSignature = Base64UrlEncode(signature);

 string jwtToken = $"{encodedHeader}.{encodedPayload}.{encodedSignature}";

 return jwtToken;}

nats-server.conf

**# Account configuration**
 accounts {
    AUTH: {
    users: [{ user: auth, password: auth }]
},
SYS: {},
ACC: {}
}

**# Authorization & Auth Callout Configuration**
authorization {
auth_callout {
    account: AUTH
    users: ["auth"]
    issuer: 
"ABC53VGEEBXCIWW4AJKLL2JMVPUUXXF74LCM3Q6AHLPWKH5JLDO7VCGQ"
}
}

**# Set system account**

system_account: SYS