UnityWebRequest read body response

Hy, I am trying to read the body response from a call to a server. The problem is that I get this error: NullReferenceException: Object reference not set to an instance of an object

I can read the header when I do the UnityWebRequest call. The person gets added to the database on the server. I just can't get to the body of the respons. I need it so i can use the id in the app. Can sombedoy help me?

this is my code:

     public void startButton()
   {
     StartCoroutine(CreateUser());

 }

 IEnumerator CreateUser()
 {
     testclass myObject = new testclass();
     myObject.email = "testmail@test.be";
     myObject.password = "svhdshkhqfgv";
     string jsonStringTrial = JsonUtility.ToJson(myObject);
     byte[] bodyRaw = new System.Text.UTF8Encoding().GetBytes(jsonStringTrial);
    

     var request = new UnityWebRequest("https://www.googleapis.com/identitytoolkit/v3/relyingparty/signupNewUser?key=serverapi", "POST");

    
     request.uploadHandler = (UploadHandler)new UploadHandlerRaw(bodyRaw);

     yield return request.SendWebRequest();

     if (request.isNetworkError || request.isHttpError)
     {
         Debug.Log(request.error);
     }
     else
     {
         Debug.Log("Form upload complete!");
         Debug.Log(request.responseCode);
         Debug.Log("server response status: " + request.responseCode);
         Dictionary<string, string> responseHeaders = request.GetResponseHeaders();
         Debug.Log(responseHeaders.Keys);
      

         foreach (KeyValuePair<string, string> entry in request.GetResponseHeaders())
         {
             Debug.Log(entry.Value + "=" + entry.Key);
         }

         Debug.Log(request.downloadHandler.text);       

        
     }

 }