Customizing WooCommerce Thank You page with Filters

add_filter( 'the_title', 'woo_title_order_received', 10, 2 );

function woo_title_order_received( $title, $id ) {
    if ( function_exists( 'is_order_received_page' ) &&
         is_order_received_page() && get_the_ID() === $id ) {
        $title = "Thank you for your order! :)";
    }
    return $title;
}

add_filter( 'woocommerce_thankyou_order_received_text', 'fahim_thank_you_title', 20, 2 );

function fahim_thank_you_title( $thank_you_title, $order ){

    return 'Oh ' . $order->get_billing_first_name() . ', thank you so much for your order!';

}

# https://www.tychesoftwares.com/how-to-customize-the-woocommerce-thank-you-page/
# https://rudrastyh.com/woocommerce/thank-you-page.html