Securing Typeform Webhook Python

I'm trying to accept form responses from Typeform using Python/Django/DRF and am having trouble authenticating the webhook request due to not being able to get the hashes to match.

Here are the instructions from Typeform:

11. Using the HMAC SHA-256 algorithm, create a hash (using created_token as a key) of the entire received payload as binary.
22. Encode the binary hash in base64 format.
33. Add prefix sha256= to the binary hash.
44. Compare the created value with the signature you received in the Typeform-Signature header from Typeform.

authentication.py

1class TypeformAuthentication(authentication.BaseAuthentication):
2    def authenticate(self, request):
3        typeform_signature = request.META.get('HTTP_TYPEFORM_SIGNATURE')
4        data = request.body
5        secret_key = os.environ.get('TYPEFORM_SECRET_KEY')
6
7        if not typeform_signature:
8            return None
9
10        if typeform_signature:
11            hash = hmac.new(bytes(secret_key, encoding='utf-8'), data, hashlib.sha256)
12            actual_signature = 'sha256={}'.format(base64.b64encode(hash.digest()).decode())
13            user = User.objects.get(username='typeform-user')
14            if actual_signature == typeform_signature:
15                 return(user, None)
16            else:
17                raise exceptions.AuthenticationFailed('Typeform signature does not match.')
18        else:
19            return None

Example payload

1{
2  "event_id": "01DTXE27VQSA3JP8ZMP0GF9HCP",
3  "event_type": "form_response",
4  "form_response": {
5    "form_id": "OOMZur",
6    "token": "01DTXE27VQSA3JP8ZMP0GF9HCP",
7    "landed_at": "2019-11-30T05:55:46Z",
8    "submitted_at": "2019-11-30T05:55:46Z",
9    "definition": {
10      "id": "OOMZur",
11      "title": "Auto Liability (New Company)",
12      "fields": [
13        {
14          "id": "GnpcIrevGZQP",
15          "title": "What is your business name?",
16          "type": "short_text",
17          "ref": "3e60e064-f14c-4787-9968-0358e8f34468",
18          "properties": {}
19        }
20      ]
21    },
22    "answers": [
23      {
24        "type": "text",
25        "text": "Lorem ipsum dolor",
26        "field": {
27          "id": "GnpcIrevGZQP",
28          "type": "short_text",
29          "ref": "3e60e064-f14c-4787-9968-0358e8f34468"
30        }
31      }
32    ]
33  }
34}

Typeform Generated Hash

sha256=jdzKuFkijyBIMvmGyveHfcfzcNXUeQCuveNGP6CEdXk=

authentication.py Generated Hash