I'm trying to connect to Discord's OAuth endpoint using Client credential grant ( Found that there's a Replace which swaps out for in FormUrlEncodedContent Ended up making my own version of ByteArrayContent/FormUrlEncodedContent

public class CustomFormUrlEncodedContent : ByteArrayContent
{
        public CustomFormUrlEncodedContent(
            IEnumerable<KeyValuePair<string, string>> nameValueCollection)
            : base(GetContentByteArray(nameValueCollection))
        {
            Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");
        }

        private static byte[] GetContentByteArray(IEnumerable<KeyValuePair<string?, string?>> nameValueCollection)
        {
            if (nameValueCollection == null)
            {
                throw new ArgumentNullException(nameof(nameValueCollection));
            }

            // Encode and concatenate data
            StringBuilder builder = new StringBuilder();
            foreach (KeyValuePair<string?, string?> pair in nameValueCollection)
            {
                if (builder.Length > 0)
                {
                    builder.Append('&');
                }

                builder.Append(Encode(pair.Key));
                builder.Append('=');
                builder.Append(Encode(pair.Value));
            }

            return Encoding.GetEncoding(28591).GetBytes(builder.ToString());
        }

        private static string Encode(string? data)
        {
            if (string.IsNullOrEmpty(data))
            {
                return string.Empty;
            }
        // Escape spaces as ' '.
        return Uri.EscapeDataString(data);//.Replace(" ", " ");
        }
}