WHMCS billing system has its payment gateway module from CoinPayments.com

Unlike other payment gateways, CoinPayments one instantly redirects to their website when on Invoice page i select their payment gateway. Other payment gateways properly waiting for person to click "Pay Now" button.

How to fix?

Edit file \upload\modules\gateway\coinpayments.php

comment out or remove following line:

$code .= '<script type="text/javascript">document.forms["cpsform"].submit();</script>';

(it is at line 50)

it will disable auto-redirection and show a payment button instead