bookish_admin-1.0.x-dev/modules/bookish_contact/bookish_contact.install

<?php

/**
 * @file
 * Contains install hooks for the Bookish Contact module.
 */

use Drupal\menu_link_content\Entity\MenuLinkContent;
use Drupal\user\Entity\Role;

/**
 * Implements hook_install().
 */
function bookish_contact_install() {
  $anonymous_role = Role::load(Role::ANONYMOUS_ID);
  $anonymous_role->grantPermission('access site-wide contact form');
  $anonymous_role->save();
  $contact_settings = \Drupal::configFactory()->getEditable('contact.settings');
  $contact_settings->set('default_form', 'contact_me');
  $contact_settings->save();

  $menu_link = MenuLinkContent::create([
    'enabled' => TRUE,
    'title' => t('contact'),
    'menu_name' => 'main',
    'link' => ['uri' => 'internal:/contact/'],
    'weight' => 15,
  ]);
  $menu_link->save();
}