Example: C#

using System;using System.Text;using System.Collections.Generic;using System.Security.Cryptography;using System.Web.Script.Serialization;namespace VxTokenGenerator{    class TokenGenerator    {        static void Main(string[] args)        {            Console.WriteLine(vxGenerateToken("secret", "issuer", 1559359105, "join", 123456, "sip:.username.@domain.vivox.com", "sip:confctl-g-channelname@domain.vivox.com"));        }        static string vxGenerateToken(string key, string issuer, int exp, string vxa, int vxi, string f, string t)        {            var claims = new Claims            {                iss = issuer,                exp = exp,                vxa = vxa,                vxi = vxi,                f = f,                t = t            };            List<string> segments = new List<string>();            // Header is static - base64url encoded {} - Can also be defined as a constant "e30"            var header = Base64URLEncode("{}");            segments.Add(header);            // Encode payload            var claimsString = new JavaScriptSerializer().Serialize(claims);            var encodedClaims = Base64URLEncode(claimsString);            // Join segments to prepare for signing            segments.Add(encodedClaims);            string toSign = String.Join(".", segments);            // Sign token with key and SHA256            string sig = SHA256Hash(key, toSign);            segments.Add(sig);            // Join all 3 parts of token with . and return            string token = String.Join(".", segments);            return token;        }        private static string Base64URLEncode(string plainText)        {            var plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);            // Remove padding at the end            var encodedString = System.Convert.ToBase64String(plainTextBytes).TrimEnd('=');            // Substitute URL-safe characters            string urlEncoded = encodedString.Replace("+", "-").Replace("/", "_");            return urlEncoded;        }        private static string SHA256Hash(string secret, string message)        {            var encoding = new System.Text.ASCIIEncoding();            byte[] keyByte = encoding.GetBytes(secret);            byte[] messageBytes = encoding.GetBytes(message);            // The instance of HMACSHA256 is constructed and disposed in this method because it is not thread safe            using (var hmacsha256 = new HMACSHA256(keyByte))            {                byte[] hashmessage = hmacsha256.ComputeHash(messageBytes);                var hashString = Convert.ToBase64String(hashmessage).TrimEnd('=');                string urlEncoded = hashString.Replace("+", "-").Replace("/", "_");                return urlEncoded;            }        }        public class Claims        {            public string iss { get; set; }            public int exp { get; set; }            public string vxa { get; set; }            public int vxi { get; set; }            public string f { get; set; }            public string t { get; set; }            public string sub { get; set; }        }    }}