PayPal IPN simulator returning “INVALID” but I've followed the rules

Question

So I have a PHP service that\'s only job is to accept PayPal IPN connections. I\'m using PSR7 $request->getBody()->getContents() to get the following from

Answer 1

The PayPal transaction validation always returns INVALID if the IPN comes from the IPN simulator, but I found a workaround. If the IPN will come from a real transaction, it works fine. Here is how I did.

1. Go to PayPal Developer and Login
2. Create a sandbox account (if you already have a sandbox account, ignore these 2 steps)
3. Now go to https://www.sandbox.paypal.com and login
4. Then visit button management and create a button
5. Don't forget to set the IPN notification URL for your sandbox acccount
6. Now make a real tracaction from the button you created in the sandbox account
7. It works flawlessly