Web Forms :: Unable To Integrate With VoicePay Payment?

Following below is code to integrate with voice pay

<form action="https://secure.voice-pay.com/gateway/remote" method="post">
<input type="hidden" name="auth_id" value="" /> // our ID
<input type="hidden" name="auth_pass" value="" /> // our Password
<input type="hidden" name="card_num" value="4000000000000002" />
<input type="hidden" name="card_cvv" value="123" />
<input type="hidden" name="card_expiry" value="0112" />
<input type="hidden" name="cust_name" value="Testing" />
<input type="hidden" name="cust_address" value="sss" />
<input type="hidden" name="cust_country" value="GB" />
<input type="hidden" name="cust_ip" value="123.45.67.89" />
<input type="hidden" name="cust_email" value="test@test.com" />
<input type="hidden" name="tran_ref" value="1" />
<input type="hidden" name="tran_amount" value="9.99" />
<input type="hidden" name="tran_currency" value="GBP" />
<input type="hidden" name="tran_testmode" value="1" />
<input type="hidden" name="tran_type" value="Sale" />
<input type="hidden" name="tran_class" value="MoTo" />
<input type="submit" value="Buy Now" />
</form>

This page is hosted at Secure server(HTTPS) and our secure server's IP address is added in our voice pay account's whitelist.

I got response: V|99E4C999018|000|V226|Invalid request

now support people said that:

" This request came from IP address 123.45.67.89 - which is not in your list of allowed IP addresses.

This is your browser IP address, not the server IP address.

The request is being submitted by the users browser, rather than being sent from the server. "

According to them, The request must come from a server, where as i have not written code for sending request from browser not from the server.