code: public void showAlertAddDialog(HttpMessage httpMessage, int historyType) {
          if (dialogAlertAdd == null || !dialogAlertAdd.isVisible()) {
              dialogAlertAdd = new AlertAddDialog(getView().getMainFrame(), false);
              dialogAlertAdd.setHttpMessage(httpMessage, historyType);
              dialogAlertAdd.setVisible(true);
          }
      }
docs: Shows the Add Alert dialogue, using the given {@code HttpMessage} and history type for the {@code HistoryReference} that
  will be created if the user creates the alert. The current session will be used to create the {@code HistoryReference}.
  The alert created will be added to the newly created {@code HistoryReference}.
  <p>
  Should be used when the alert is added to a temporary {@code HistoryReference} as the temporary {@code HistoryReference}s
  are deleted when the session is closed.
  
  @param httpMessage the {@code HttpMessage} that will be used to create the {@code HistoryReference}, must not be
  {@code null}.
  @param historyType the type of the history reference that will be used to create the {@code HistoryReference}.
  @since 2.7.0
  @see Model#getSession()
  @see HistoryReference#HistoryReference(org.parosproxy.paros.model.Session, int, HttpMessage)