MapAttribute troubles

[AlexMF26]

Hello, I have some troubles using PynamoDB's MapAttribute My models looks like this:

class UserModel(Model):

    class Meta:
        table_name = f'user_info-{settings.stage}'
        region = 'eu-central-1'

    id = UnicodeAttribute(hash_key=True)
    dremio = DremioMap(null=True)

class DremioMap(MapAttribute):
    acknowledgment: AcknowledgmentMap()
    certificate: CertificateMap()

class CertificateMap(MapAttribute):
    certificate_location: UnicodeAttribute()
    certificate_date: UnicodeAttribute()

class AcknowledgmentMap(MapAttribute):
    acknowledgment: UnicodeAttribute()
    acknowledgment_date: UnicodeAttribute()

I get an ValueError: Attribute certificate_location specified does not exist when I try to instantiate CertificateMap in the following method:

async def add_dremio(user_id: str, certificate_path: str, acknowledgment_content: str):
    current_date = date.today().isoformat()
    user = UserModel.get(user_id)
    certificate = CertificateMap(certificate_location=certificate_path,
                                 certificate_date=current_date)
    acknowledgment = AcknowledgmentMap(acknowledgment=acknowledgment_content,
                                       acknowledgment_date=current_date)
    dremio = DremioMap(acknowledgment=acknowledgment, certificate=certificate)
    user.update(actions=[UserModel.dremio.set(dremio)])
    user = UserModel.get(user_id)
    return user

Traceback:

Traceback (most recent call last):
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/uvicorn/protocols/http/h11_impl.py", line 396, in run_asgi
    result = await app(self.scope, self.receive, self.send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/uvicorn/middleware/proxy_headers.py", line 45, in __call__
    return await self.app(scope, receive, send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/fastapi/applications.py", line 199, in __call__
    await super().__call__(scope, receive, send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/applications.py", line 111, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/middleware/errors.py", line 181, in __call__
    raise exc from None
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/middleware/errors.py", line 159, in __call__
    await self.app(scope, receive, _send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/exceptions.py", line 82, in __call__
    raise exc from None
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/exceptions.py", line 71, in __call__
    await self.app(scope, receive, sender)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/routing.py", line 566, in __call__
    await route.handle(scope, receive, send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/routing.py", line 227, in handle
    await self.app(scope, receive, send)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/starlette/routing.py", line 41, in app
    response = await func(request)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/fastapi/routing.py", line 201, in app
    raw_response = await run_endpoint_function(
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/fastapi/routing.py", line 148, in run_endpoint_function
    return await dependant.call(**values)
  File "/data/alex/git/python-microservices/api-user-info/src/resources/users/router.py", line 36, in post_dremio
    certificate = CertificateMap(certificate_location=location,
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 826, in __init__
    AttributeContainer.__init__(self, **attributes)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 278, in __init__
    self._set_attributes(**attributes)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 960, in _set_attributes
    super()._set_attributes(**attrs)
  File "/data/alex/git/python-microservices/api-user-info/.venv/lib/python3.9/site-packages/pynamodb/attributes.py", line 337, in _set_attributes
    raise ValueError("Attribute {} specified does not exist".format(attr_name))
ValueError: Attribute certificate_location specified does not exist