Protecting the generated PDF in C# with RestSharp

using RestSharp;
using System.IO;
using System.Threading.Tasks;

// You can get an API key at https://pdfshift.io
var apiKey = "sk_xxxxxxxxxxxx";

var client = new RestClient("https://api.pdfshift.io/v3/convert/pdf");
var request = new RestRequest(Method.Post);
request.AddHeader("X-API-Key", apiKey);
request.AddHeader("Content-Type", "application/json");

var payload = new
{
    source = "https://www.example.com",
    // Protect the PDF with a password
    protection = new
    {
        user_password = "user123",
        owner_password = "owner123"
    }
};

request.AddJsonBody(payload);

var response = await client.ExecuteAsync(request);

// Handle errors:
if (response.StatusCode >= System.Net.HttpStatusCode.BadRequest)
{
    throw new Exception($"Request failed with status code {response.StatusCode}");
}

File.WriteAllBytes("result.pdf", response.RawBytes);

Console.WriteLine("The PDF document was generated and saved to result.pdf");