post meta as post name

add_filter( 'wp_insert_post_data', 'prefix_insert_post_data', 10, 3);
/**
 * Filter the post data just before it goes to the database.
 *
 * Inserts custom fields into the post name and post title.
 *
 * @param array $data An array of slashed post data.
 * @param array $postarr An array of sanitized, but otherwise unmodified post data.
 * @return array
 */
 function prefix_insert_post_data( array $data, array $postarr ) : array {
 
  // Return if not on proper post type.
  if ( ! in_array( $data['post_type'], array('post'), true ) ) {
    return $data;
  }
  
  $post_meta = get_post_meta( get_the_ID(), 'post_meta_key', true );

  $data['post_title'] = wp_kses_post( $post_meta );
  $data['post_name']  = sanitize_title_with_dashes( $post_meta );

  return $data;
}