Why doesn't the pre_get_document_title filter work?

Question

WordPress

Trying to use the wp_get_document_title function in a plugin

add_action( 'after_setup_theme', 'theme_functions' );
function theme_functions() {
    add_theme_support( 'title-tag' );
}

add_filter( 'pre_get_document_title','sm_pre_get_document_title');
function pre_get_document_title(){
  global $post;
  if( $post->ID != 6486 ) return; 
  return 'Тест';
}

the title of the page with id 6486 does not change, in which direction to dig?

Answer 1

filter function is called wrong

add_filter( 'pre_get_document_title','sm_pre_get_document_title');
function sm_pre_get_document_title( $param ){
  global $post;
  if( $post->ID != 6486 ) return; 
  return 'Тест';
}