In this article, I'll show you how to add Twig Template Suggestions for checkboxes Elements in drupal 8 with THEMENAME_theme_suggestions_checkboxes_alter():
/**
* @param array $suggestions
* @param array $variables
*/
function THEMENAME_theme_suggestions_checkboxes_alter(array &$suggestions, array $variables, $hook) {
if (isset($variables['element']['#id'])) {
$id = str_replace("-", "_", $variables['element']['#id']);
$suggestions[] = $hook . '__' . $id;
}
}
