UpdateDynamicsRecordAsyncSample.cs

public static async Task UpdateDynamicsRecordAsync(string recordId, string updateData)
{
    using (var httpClient = new HttpClient())
    {
        // Assume GetAccessTokenAsync is a helper method to retrieve the access token
        var token = await GetAccessTokenAsync("https://your-dynamics-url/");
        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
        
        var content = new StringContent(updateData, Encoding.UTF8, "application/json");
        var response = await httpClient.PatchAsync($"https://your-dynamics-url/api/data/v9.0/records({recordId})", content);
        response.EnsureSuccessStatusCode();
    }
}