Change WooCommerce Coupon amount on the fly (programmatically)

functions.php

<?php
add_filter('woocommerce_get_shop_coupon_data', 'fix_wc_coupon_discount_amount', 10, 3);
function fix_wc_coupon_discount_amount( $false, $data, $coupon ) {
	if (
		'yes' !== get_option( 'wcj_multicurrency_compatibility_wc_coupons', 'no' )
		|| is_admin()
		|| empty( $coupon_id = wc_get_coupon_id_by_code( $data ) )
		|| 'fixed_cart' != get_post_meta( $coupon_id, 'discount_type', true )
	) {
		return $false;
	}
	$current_coupon_amount = get_post_meta( $coupon_id, 'coupon_amount', true );
	$coupon->set_amount( $current_coupon_amount * 3 );
	return $coupon;
}