TOPIC: customise information sent to paypal

i found /components/com_dtregister/lib/payment/paypal.php but im not sure how to edit this file to customise what information gets sent to paypal.

i want the category of the event and the person's name to be sent as well as the name of the event.

thank you.

bump. this is really important for our website to work properly. thanks.

I would like the VAT charged as an extra line item.