Can the "*" character be inserted into all required attributes automatically with the "Required" option? If so, how can this be done?

Not getting exactly what you want to achieve.

Ok Thanks

I want the user to easily distinguish the required attribute, so I added "*" next to the attribute name, but this also appears in the search. How can I make it appear only in the entry-edit post?

You must add star manually to plugin files, you cannot add that via translation

I had added the star manually through configuration in both languages. In which file should I do what you suggest? Can you please give an example?

You must go to PHP files, but there usually you do not find field itself, but it's printed via loop so it's not that simple.
Will look on it in next update.

Yes, you should see it soon because it will help the user a lot to see fields that are mandatory. Thanks for the replies.

In the end it was very easy. An IT student friend put this:

($a['b_required'] == 1 ? '<span class="req">*</span>' : '') .
here (functions.php file):
 if($linked === false) {
    $html .= '<div class="control-group atr-type-' . strtolower($a['s_type']) . ' ' . ($a['s_type'] == 'CHECKBOX' ? 'atr-check-options-' . ($a['b_check_single'] == 1 ? 'single' : 'multi') : '') . '" id="atr-' . ($a['s_identifier'] <> '' ? $a['s_identifier'] : 'id' . $a['pk_i_id']) . '">';
    $html .= '<label class="control-label" for="atr' . $a['pk_i_id'] . '">' . ($name <> '' ? $name : __('New attribute', 'attributes')) . ($a['b_required'] == 1 ? '<span class="req">*</span>' : '') . '</label>';
    $html .= '<div class="controls">';
  } else {
    $html .= '<div class="atr-linked">';
  }
    and the problem is solved. Thanks again for the replies

Correct.

Ok Thanks