POST http save Screen with special characters

I try to call the endpoint https://api-worldcheck.refinitiv.com/v2/cases/saveAndScreen in C# with a name which is "RATP Réseaux" but I am returned a 401 but when I change the name to " RATP Reseaux" I have a 200. I think it's because of the "é" character but he encodes it in UTF8.

here is my function which allows you to call api

 public async Task<T?> PostRequest<T>(Uri uri, string data)
        {
            using (HttpClient client = _clientFactory.CreateClient())
            {
                HttpMethod httpMethod = HttpMethod.Post;
                Encoding encoding = Encoding.UTF8;
                string contentType = "application/json";
                HttpRequestMessage httpRequest = new HttpRequestMessage(httpMethod, uri);
                Dictionary<string, string> headers = AuthHeadersBuilder.GenerateAuthHeaders(
                    apiKey,
                    apiSecret,
                    httpMethod.Method.ToLower(),
                    uri,
                    contentType,
                    data);
                foreach (KeyValuePair<string, string> header in headers)
                {
                    httpRequest.Headers.Add(header.Key, header.Value);
                }
                httpRequest.Content = new StringContent(data, encoding, contentType);
                httpRequest.Content.Headers.ContentType = MediaTypeHeaderValue.Parse(contentType);

                var response = client.SendAsync(httpRequest).Result;

                response.EnsureSuccessStatusCode();

                var jsonContent = await response.Content.ReadAsStringAsync();
                return JsonConvert.DeserializeObject<T?>(jsonContent);
            }
        }

and my body is :

{
    "groupId": "5jb6eq4nmdc41ihi4jaus2r156",
    "providerTypes": [
        "WATCHLIST"
    ],
    "nameTransposition": true,
    "caseScreeningState": {
        "WATCHLIST": "INITIAL"
    },
    "cases": [
        {
            "entityType": "ORGANISATION",
            "name": "SNCF Réseau",
            "secondaryFields": [
                {
                    "typeId": "SFCT_192",
                    "value": "FRA"
                },
                {
                    "typeId": "SFCT_6",
                    "value": "FRA"
                },
                {
                    "typeId": "SFCT_193",
                    "value": "FR-RCS"
                },
                {
                    "typeId": "SFCT_191",
                    "value": "412280737"
                }
            ]
        }
    ]
}

Do you have a solution ?

THANKS,

PRAK Billy