Facebook sends empty POST to a webhook

Question

I am trying to install a webhook for leadgen event for my page via a facebook app. So I have:

1. Facebook Page where leads come from
2. Facebook App
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Answer 1

Facebook sends webhook data as Content-Type: application/json, not as …: application/x-www-form-urlencoded (as a normal form with method=post would.)

Therefor, PHP does not populate $_POST – you need to read the raw input stream instead. That can be done using file_get_contents('php://input') – and then just apply json_decode on that data, and you’ll have a proper data structure to work with.