Заменить BaseSettings на BaseModel

Пример кода из env_settings.py:

gitlab.dvmn.org/…/env_settings.py

class DjangoSettings(BaseSettings):
    SECRET_KEY: str
    DEBUG: bool = Field(
        default=False,
        description='Disabled by default to protect admin from credentials leak on production environment '
                    'when env param get wrong value. That happends because of param name typos '
                    'and another common configuration mistakes.',
    )
    ALLOWED_HOSTS: list[str] = ['127.0.0.1', 'localhost']
    CSRF_TRUSTED_ORIGINS: list[str] = Field(
        default=[],
        description='Trusted origins for CSRF checks.',
    )
    STATIC_URL: str = 'static/'
    MEDIA_URL: str = 'media/'
    parse_comma_separated_values = validator('ALLOWED_HOSTS', 'CSRF_TRUSTED_ORIGINS', pre=True, allow_reuse=True)(
        parse_comma_separated,
    )


class RollbarSettings(BaseSettings):
    BACKEND_TOKEN: str
    ENVIRONMENT: str


class EnvSettings(BaseSettings):
    DJ: DjangoSettings
    POSTGRES_DSN: PostgresDsn
    ...

Для вложенных схем в качествве базового класса надо использовать BaseModel вместо BaseSettings.