How to Add Subscript and Superscript in the WordPress Classic Editor

We have several clients in the medical industry, and frequently need to add superscript references. WordPress doesn’t have this feature on its toolbar by default, but you can add it by adding this simple function to your active theme’s functions.php file

function enable_additional_mce_button($buttons) {
  $buttons[] = 'superscript';
  $buttons[] = 'subscript';
  return $buttons;
}
add_filter("mce_buttons_2", "enable_additional_mce_button");