I had the opportunity to encounter a 403 error while setting up a PayPlug payment module on an OVH server with WooCommerce (WordPress).

The order goes through very well, but the notification from the PayPlug server was not reaching my server to indicate that the payment had been successfully completed.

After discussing with PayPlug support, it turns out that on some OVH servers, there is a Firewall that, even though it is disabled via the OVH back office, is still active on the server.

Therefore, you need to modify the .ovhconfig file located at the root of the server, and more specifically this line:

http.firewall=security

Replace with:

http.firewall=none

And the problem is solved!

Good luck for the rest 😉