When a customer authorizes a transaction you will receive a callback at the callback_url specified when you created a payment, the callback will be a POST request with a JSON request body in the following format:

If we fail to deliver the callback, we will retry hourly for the next 12 hours

    "id": 1000000,
    "order_id": "123",
    "state": "authorized",
    "amount": 500,
    "currency": "DKK",
    "variables": {
        "key": "value"
    "created_at": "2020-01-01 12:00:00"

By looking at the state you can determine if authorize was successful, in that case the state will be "authorized"