Where can I find the JWT when the webhook have a secret?

I'm using node with KoaJS and I'm trying to use a call event subscription, with secret and I can't find the JWT in the request received.

When I create a webhook without secret, everything works well, but if I put a secret on the webhook i can't find the JWT. I looked for it on the body, headers, params of the request and seems it is not there.

Did you have some example of decode or verify the request to me investigate what is happening?

Thanks for the help!