Alter the Shop Page title

// Alter the Shop page title
function my_alter_shop_page_header_title( $title ) {
 
    if ( is_shop() ) {
        $title = 'My shop page';
    }
 
    // Return the title
    return $title;
    
}
add_filter( 'ocean_title', 'my_alter_shop_page_header_title', 20 );

All PHP snippets should be added via a child theme's functions.php file.