Resolved UnityWebRequest report an error : SSL CA certificate error

Hey, I have this basic command and it says SSL CA certificate error in unity editor so what is the problem:

Code (CSharp):

1.  
2.     private IEnumerator SendRegistrationRequest()
3.     {
4.         // Get the user input from the InputFields
5.         string email = emailInput.text;
6.         string password = passwordInput.text;
7.         string username = usernameInput.text;
8.  
9.         WWWForm form = new WWWForm();
10.         form.AddField("registerEmail", email);
11.         form.AddField("registerPass", password);
12.         form.AddField("registerUser", username);
13.  
14.         UnityWebRequest www = UnityWebRequest.Post("https://localhost/EpicGuardiansBackEnd/RegisterUser.php", form);
15.         yield return www.SendWebRequest();
16.  
17.         if (www.result != UnityWebRequest.Result.Success)
18.         {
19.             Debug.Log(www.error);
20.         }
21.         else
22.         {
23.             Debug.Log("Form upload complete!");
24.             string response = www.downloadHandler.text;
25.             statusText.text = response;
26.         }
27.     }