The IP Address passed is the first IP Address logged to the basket. Only way to check the stored ip address for a basket though is to review the basket in the database table _cbsubs_payment_baskets. Specifically the ip_addresses column. An example API call would be something like the following.
Code:
$commission_url = $path . '/sale.php'
. '?profile=72198'
. '&idev_saleamt=100.00'
. '&idev_ordernum=S1-42-3'
. '&idev_option_1='
. '&idev_option_2='
. '&idev_option_3=42'
. '&ip_address=127.0.0.1';
idev_saleamt = raw price of the plan as seen while editing it within CBSubs > Plans
idev_ordernum = item_number value for the basket
idev_option_1 = whatever field you set for this within CBSubs > Settings > Integrations > iDevAff
idev_option_2 = whatever field you set for this within CBSubs > Settings > Integrations > iDevAff
idev_option_3 = the plans id as seen within CBSubs > Plans
ip_address = first ip addressed stored in ip_addresses within the basket
I can't provide for you an exact example for your install as you'll need to review your database and apply the necessary values for that.