I created buttons in PayPal's Sandbox environment, and have a PayPal IPN verifier set up to my proxied local URL (using ngrok):
https://12345.ngrok.io/ipn
When I complete a sale in the sandbox, it comes through within about 30 seconds to my IPN verifier, but everything is blank.
# this is the base URL: https://12345.ngrok.io/ipn
request.url
# this is empty (len() == 0)
request.args
# so is this, naturally (b'')
request.data
Why am I not getting the details of my transaction?!?
It fails similarly when creating a button with the "advanced" variable: notify_url=(the ngrok URL).
Also, something that may or may not be related is that when I try to use the IPN simulator with my ngrok URL, the tool gives me this error:
IPN was not sent, and the handshake was not verified. Review your information.
Can anyone offer any guidance on what is going wrong?