Code-Snippets-Functions/Execute a function on a child site/WooCommerce/add-a-discount-based-on-payment-method-on-checkout.txt

add_action( 'woocommerce_checkout_init', 'payment_method_change_trigger_update_checkout_js' );
function payment_method_change_trigger_update_checkout_js() {
    wc_enqueue_js("$('form.checkout').on( 'change', 'input[name=payment_method]', function(){
        $(document.body).trigger('update_checkout');
    });");
}

add_filter( 'woocommerce_cart_calculate_fees', 'discount_based_on_payment_method', 10, 1 );
function discount_based_on_payment_method( $cart ) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    if ( ! ( is_checkout() && ! is_wc_endpoint_url() ) )
        return;
    
    $targeted_payment_method = 'cheque'; // Here define the desired payment method
    
    if( WC()->session->get('chosen_payment_method') === $targeted_payment_method ) {
        $discount = $cart->subtotal * 0.10; // 10% discount
        $cart->add_fee( 'Cash Discount', -$discount);
    }
}