Require Post Title for Custom Post Type(s)

post-requirements.js

/** global jQuery */
(function ($) {
  'use strict'

  const requirements = {
    $title: $('#title')
  }

  /**
   * Initiate.
   */
  requirements.init = function () {
    requirements.$title.prop('required', true)
    $('body').on('submit.edit-post', '#post', requirements.submitListener)
  }

  /**
   * Form submit listener. If the title is empty, prevent submission.
   * - Show the alert
   * - Hide the "spinner".
   * - The buttons get "disabled" added to them on submit. Remove that class.
   * - Focus on the title field.
   */
  requirements.submitListener = function () {
    if (requirements.$title.val().replace(/ /g, '').length === 0) {
      window.alert('A title is required.')
      requirements.publishingActions('#minor-publishing-actions') // Draft
      requirements.publishingActions('#major-publishing-actions') // Publish
      return false
    }
  }

  /**
   * Trigger "publishing" actions.
   * @param {string} selector
   */
  requirements.publishingActions = function (selector) {
    const $publishingActions = $(selector)
    $publishingActions.find('.spinner').removeClass('is-active')
    $publishingActions.find(':button, :submit, a.submitdelete, #post-preview').removeClass('disabled')
    requirements.$title.trigger('focus')
  }

  $(document).ready(function () {
    $(function () {
      requirements.init()
    })
  })
}(jQuery))

require-post-title.php

<?php

const HANDLE_PUBLISH_REQUIREMENTS = 'publish-requirements';

add_action('admin_enqueue_scripts', static function(string $hook_suffix): void {
    if (!\in_array($hook_suffix, ['post.php', 'post-new.php'], true)) {
        return;
    }

    /**
     * This is assuming your are using my PluginFactory
     * @link https://github.com/thefrosty/wp-utilities/blob/develop/src/Plugin/PluginFactory.php
     */
    \wp_register_script(
        self::HANDLE_PUBLISH_REQUIREMENTS,
        $this->getPlugin()->getUrl('assets/js/post-requirements.js'),
        ['jquery'],
        '20220301',
        true
    );
    \wp_enqueue_script(self::HANDLE_PUBLISH_REQUIREMENTS);
} );