gettransactionIDandtransactionreferencefromredirectsreturnUrlandcancelUrl

This issue is not about server to server.

For Paypal Express gateway call

need pass array with from paypal-added get params

and

values. (example: mygw.local/some-callback/?token=EC-23981419811YC530N&PayerID=9A2UUTPUJB238)
Other payment systems can add their own parameters to

and

.

In my case, the

and

pages located on another site and cannot call

. But I can create an my own wrapper for

and

for parse get-params generated by payment system and

to final

or

.

The problem is to unify the parsing of generated by payments systems get parameters added to

and

. The gateways that I use now do not provide separate methods for perverting these parameters and mapping them into omnipay-specific names. For example - convert Paypal Express

param from

or

to omnipay

.

Thanks man i was stuck where i was getting returned after the checkout and there was nothing to do .By reading your comment the logic becomes fully clear to me and i just complete sandbox payment successfully.Thanks man