Discount Referrer Pseudo Code

refer-discount.php

<?php

add_action('woocommerce_before_cart_table', 'discount_frol_url');
function discount_from_url() {
    global $woocommerce;
    if( 'https://wpsessions.com' == wp_get_referer() ) {
        $coupon_code = 'WPSESSIONS';
        if (!$woocommerce->cart->add_discount( sanitize_text_field( $coupon_code ))) {
            $woocommerce->show_messages();
        }
        echo '<div class="woocommerce_message"><strong>Hello WPSessions Person! a Discount code has been automatically applied!</strong></div>';
    }
}