Hey guys 
I’ve been trying to setup the Webhooks and so far it’s been okay… until i tested the webhook itself.
I have requested and have been granted access to the Beta.
I have granted the “Read, Write and Access direct messages” permissions to my app.
I have registered my webhook using this fine helper: https://gist.github.com/jcipriano/4820fe05152769cc87d4322897755707
I got the id out of the create-webhook-config request and have used it in add-subsciption which printed me a nice “Subscription added”
Easy enough 
The part i don’t really have and struggle to debug is that my webhook is never called…
I have used my personnal twitter account to send a direct message to the Page DemoVeloParis which is the account associated to my app, but the webhook is just not called…
My webhook looks something like that: https://SOME_ID.ngrok.io/reviews/twitter/message/
Thank you guys for helping 