Fix Edit Slug Button Missing Issue in WordPress

edit-slug-button-missing-in-wordpress.php

<?php

/**
 * Changes all post links to the format 'newsroom/news/yyyy/mm/dd/%postname%'
 *
 * @param  string  $url  The post URL.
 * @param  WP_Post $post The post.
 * @return string  $url  The modified URL.
 */
function km_filter_post_links( $url, $post ) {

   if ( 'post' === $post->post_type ) {

      // If $url contains %postname% placeholder
      if ( false !== strpos( $url, '%postname%' ) ) {
         $slug = '%postname%';
      } elseif ( $post->post_name ) {
         $slug = $post->post_name;
      } else {
         $slug = sanitize_title( $post->post_title );
      }

      $date = DateTime::createFromFormat( 'Y-m-d H:i:s', $post->post_date )->format( 'Y/m/d' );
      $url  = home_url( user_trailingslashit( 'newsroom/news/' . $date . '/' . $slug ) );

   }

   return $url;

}
add_filter( 'post_link' , 'km_filter_post_links', 10, 2 );


/**
 * Filter posts preview links to point to the correct URL.
 *
 * @param  string  $preview_link The preview link URL.
 * @param  WP_Post $post         The post.
 * @return string  $url          The modified link URL.
 */
function km_filter_post_preview_link( $preview_link, $post ) {

   if ( 'post' === $post->post_type ) {

      $preview_link = add_query_arg( array(
         'p'       => $post->ID,
         'preview' => 'true',
      ), home_url( '/' ) );

   }

   return $preview_link;

}
add_filter( 'preview_post_link', 'km_filter_post_preview_link', 10, 2 );