wordpress menu add icon

1add_filter( 'menu_image_default_sizes', function($sizes){
2  
3  // remove the default 36x36 size
4  unset($sizes['menu-36x36']);
5  
6  // add a new size
7  $sizes['menu-50x50'] = array(50,50);
8  
9  // return $sizes (required)
10  return $sizes;
11  
12});
13