functions.php

function add_theme_support_child() {
    error_log('add_theme_support_child');
    add_theme_support( 'title-tag' );


}
add_action( 'after_setup_theme', 'add_theme_support_child', 11 );

/**
 * Change title of a page conditionally
 * 
 * @return $title - type array
 * $title['title'] - Page Title
 * $title['tagline'] - Site Tagline
 */
function change_title_for_a_template( $title ) {
    error_log('change_title_for_a_template');
    // Check if current page template is 'template-homepage.php'
    // if ( is_page_template( 'template-homepage.php' ) ) {
        $title['title'] = 'Changed title for a template';
    // }

    return $title;

}

add_filter( 'document_title_parts', 'change_title_for_a_template' );