If you are using Drupal’s core Contact module and yet the form is not showing up from the menu, check on the following:

  1. Check if the contact module is enabled and in use under the modules listings page 
  2. Check if the menu is enabled under the Main navigation menu and is set to publicly displayed. You can verify this from the menu management page Structure > Menus > Main menu (/admin/structure/menu/manage/main)
  3. Check if permissions is enabled for the Anonymous user group. You can confirm this from the People > Permissions settings page > filter by Contact (/admin/people/permissions)