Add information about the price in installments after price on product page

functions.php

<?php

new studiowp_single_product_price_installments( $parts_count = 4, $factor = 1.2 );
class studiowp_single_product_price_installments {

    private $add_installment_price = false;
    private $parts_count;
    private $factor;

    public function __construct( $parts_count = 12, $factor = 1.1 ) {
        $this->parts_count = $parts_count;
        $this->factor = $factor;
	    add_filter( 'woocommerce_get_price_html', array( $this, 'woocommerce_get_price_html' ), 10, 2 );
	    add_action( 'woocommerce_before_single_product_summary', array( $this, 'woocommerce_before_single_product_summary' ) );
	    add_action( 'woocommerce_after_single_product_summary', array( $this, 'woocommerce_after_single_product_summary' ) );
    }

    public function woocommerce_before_single_product_summary() {
        $this->add_installment_price = true;
    }

	public function woocommerce_after_single_product_summary() {
		$this->add_installment_price = false;
	}

	public function woocommerce_get_price_html( $price, $product ) {
		if ( $this->add_installment_price ) {
			$single_part = $product->get_price() * $this->factor / $this->parts_count;
			$single_part = ceil( $single_part );
			$price .= sprintf(' lub <strong>%s</strong> w %d ratach', wc_price( $single_part ), $this->parts_count );
		}
		return $price;
	}

}