How can I display filter guidelines/tips below field for text formats?
namespace Drupal\my_module;

use Drupal\editor\Entity\Editor;
use Drupal\editor\Element;

/**
 * Defines a service for Text Editor's render elements.
 */
class CustomElement extends Element {

  /**
   * Additional #pre_render callback for 'text_format' elements.
   */
  public function preRenderTextFormat(array $element) {

    $element = parent::preRenderTextFormat($element);

    $format_ids = array_keys($element['format']['format']['#options']);

    // Early-return if no text editor is associated with any of the text formats.
    $editors = Editor::loadMultiple($format_ids);
    
    // Hide the text format's filters' guidelines of those text formats that have
    // a text editor associated: they're rather useless when using a text editor.
    foreach ($editors as $format_id =&gt; $editor) {
      // Display filter guidelines.
      $element['format']['guidelines'][$format_id]['#access'] = TRUE;
    }

    return $element;


function my_module_core_element_info_alter(&amp;$types) {

  $types['text_format']['#pre_render'][] = 'my_module.element.editor:preRenderTextFormat';
}

function my_module_module_implements_alter(&amp;$implementations, $hook) {
  switch ($hook) {
    case 'element_info_alter':
      $group = $implementations['my_module'];
      unset($implementations['my_module']);
      $implementations['my_module'] = $group;
      break;
  }
}

Above piece of code worked me and defined this service.