RestSharp response forbidden - api

Question

I trying get a simple request to https://c-cex.com/t/prices.json
If i use this url in browser the correct response is showed , but if i make the same request using RestRequest i receive the 403 error Forbidden in all times. i trying HttpClient,WebRequest i get the same error
I put the header with user-agent, no cache and a lot of another values but did not work
Any ideas about this problem?
Dim url As String = "https://c-cex.com/t/prices.json"
Dim client As New RestSharp.RestClient(url)
Dim request = New RestRequest(url, Method.GET)
Dim response = client.Execute(request)
Updated code with apisign request
Dim nonce As String = CInt((DateTime.UtcNow - New DateTime(1970, 1, 1)).TotalSeconds).ToString
Dim url As String = "https://c-cex.com/t/api.html?a=getbalance&currency=BTC&apikey=" & API_KEY & "&nonce=" & nonce
Dim keybytes() = UnicodeEncoding.ASCII.GetBytes(API_SECRET)
Dim hs As System.Security.Cryptography.HMACSHA512 = New System.Security.Cryptography.HMACSHA512(keybytes)
Dim urlbytes() = UnicodeEncoding.ASCII.GetBytes(url)
Dim sh() = hs.ComputeHash(urlbytes)
Dim client As New RestSharp.RestClient(url)
Dim request = New RestRequest(url, Method.GET)
request.AddHeader("Cache-Control", "no-cache")
request.AddHeader("apisign", HttpUtility.UrlEncode(ToHexString(sh)))
Dim response = client.Execute(request)

Answer 1

I am getting the response without providing the header information and It looks given piece of code is working correctly for me in VB and C#.As a best practice, base URL needs to be specified in RestClient and relative URL in RestRequest.
Please recheck without adding the request header information
VB:
Imports RestSharp
Module Module1
Sub Main()
Dim host As String = "https://c-cex.com"
Dim endpoit As String = "t/prices.json"
Dim client As New RestSharp.RestClient(host)
Dim request = New RestRequest(endpoit, Method.GET)
Dim response = client.Execute(request)
Console.WriteLine("Response Body " + response.Content)
Console.WriteLine("Response Code " + response.StatusDescription)
End Sub
End Module
C#:
String host = "https://c-cex.com";
String endpoint = "t/prices.json";
RestClient _restClient = new RestClient(host);
var request = new RestRequest(endpoint, Method.GET);
var response = _restClient.Execute(request);
Console.WriteLine("Response Body :"+response.Content);
Console.WriteLine("Response Status Code :" + response.StatusDescription);