@property<EOL><INDENT>def plan_id(self):<DEDENT>
return self._plan_id<EOL>
Gets the plan_id of this RenewTokenResponse.
The ID of the [subscription](https://docs.connect.squareup.com/api/connect/v1/#navsection-subscriptionmanagement) plan the merchant signed up for. Only present if the merchant signed up for a subscription during authorization.

:return: The plan_id of this RenewTokenResponse.
:rtype: str