Webhook for custom shipping return error

I’ve activated the webhook shipping, but the Snipcart form returns an error, while the webhook log in the dashboard has a 200 status and the response content is the json example that our doc shows.
What’s wrong?

{"rates":[{"cost":10,"description":"10$ shipping"},{"cost":20,"description":"20$ shipping","guaranteedDaysToDelivery":5},{"cost":30,"description":"30$ shipping"}]}

What I’m doing wrong?

Hey @Scandella

For the sake of the community, as I replied to you via our support line, the content-type of your response must be “application/json” to be treated correctly.