ruby on rails - How to set that the referer is the PayPal? -

after paypal payment redirects me website. how can set user redirected paypal?

i did try next variants:

request.env["http_referer"] request.referer uri(request.referer).path 

but nothing.

and 1 more question, can catch referer paypal or user did it, redirect, online tools, fabricated or no?

this paypal's pdt feature for. sends secure variables transaction made, can verify via postback paypal paypal's aynchronous notification system ipn. here's how:

https://developer.paypal.com/docs/classic/paypal-payments-standard/integration-guide/paymentdatatransfer/