Custom images for featured pages

custom_featured_pages_imgs.php

add_filter('fpc_img_id', 'my_fp_imgs', 20, 3);
function my_fp_imgs( $fpc_img_id, $fp_single_id, $featured_page_id){
  $page_img = array(
    // page_id => img_id
    '2' => '37',
  );
  
  if ( array_key_exists($featured_page_id, $page_img) ){
    return $page_img[$featured_page_id];    
  }
  return $fpc_img_id;
}