I've recently been able to successfully complete a purchase with the PayPal Sandbox and had POST variables available after the purchase, which redirects to a submission form page (which should only be viewable after payment) on payment:
array(30) { ["payer_email"]=> string(36) "example.com" ["payer_id"]=> string(13) "4FUN7NBSC787C" ["payer_status"]=> string(8) "VERIFIED" ["first_name"]=> string(4) "John" ["last_name"]=> string(3) "Doe" ["address_name"]=> string(12) "Tester Tests" ["address_street"]=> string(12) "3000 Pine St" ["address_city"]=> string(7) "Testing" ["address_country_code"]=> string(2) "GB" ["address_zip"]=> string(8) "SW1A 1AA" ["residence_country"]=> string(2) "GB" ["txn_id"]=> string(17) "4JL40298VT457961L" ["mc_currency"]=> string(3) "USD" ["mc_fee"]=> string(4) "0.33" ["mc_gross"]=> string(4) "1.00" ["protection_eligibility"]=> string(8) "ELIGIBLE" ["payment_fee"]=> string(4) "0.33" ["payment_gross"]=> string(4) "1.00" ["payment_status"]=> string(9) "Completed" ["payment_type"]=> string(7) "instant" ["handling_amount"]=> string(4) "0.00" ["shipping"]=> string(4) "0.00" ["quantity"]=> string(1) "1" ["txn_type"]=> string(10) "web_accept" ["payment_date"]=> string(20) "2020-07-19T20:05:47Z" ["business"]=> string(36) "example.com" ["receiver_id"]=> string(13) "LTCCDM4GCQZKW" ["notify_version"]=> string(11) "UNVERSIONED" ["custom"]=> string(11) "alreadyPaid" ["verify_sign"]=> string(56) "AcUCovblmWr2tKRnFCWWVIV11FyiA6BhiCk05j3nsD6ht3wW7G7A4Jxa" }
I inserted the following code within the "Advanced Variables" section of the button to do this:
return=https://example.com/submit-details-test/
rm=2
custom=alreadyPaid
However, when I attempt to make a live purchase with a real PayPal account with a real payment button, inserting the same code (changing the return URL to reflect my actual site) within the "Advanced Variables", the POST array is empty on return.
I, at the very least, need that custom variable alreadyPaid to be returned so we can verify that a person has paid before letting them view the form submission page.
Are there specific settings that must be set in the live PayPal account to use this (or can I not receive POST data back on the return URL, but only through setting up IPN?)?
