Create a TOTP factory by passing create_totp_factory either an env_var
or file_path keyword argument, just as you do when instantiating a Yosai instance.
It is important that the application creating TOTP instances uses the same configuration as Yosai to verify tokens.
>>> from yosai.core import create_totp_factory
# you can pass EITHER an environment_variable OR filepath:
>>> TOTPFactory = create_totp_factory(env_var='YOSAI_SETTINGS')