Openstack database create instance BadRequestException

Question

I used openstack sdk for create new database instance, but it raise error BadRequestException:

BadRequestException: 400: Client Error for url: 
[URL]:8779/v1.0/ab77ed8ae3f744f4baf4fb7bc97848cc/instances,
Resource None cannot be found.

My data:

data: dict = {'name': 'nhinn-db-01',
 'nics': [{'net-id': 'd57e7864-5961-4a64-a5ce-005e05d71ccf'}],
 'datastore': {'type': 'mysql', 'version': '5.7.31'},
 'flavor': object Flavor
}

conn: Connection
conn.database.create_instance(**data)