You still have access to your account when your free trial expires. Additionally, all data and progress are saved. However, you will not be able to view this data, and it will appear as shown below. If you created Dynamic QR Codes during the trial, they will deactivate and link to a service page. With an account upgrade, you can reactivate your Dynamic QR Codes and use them beyond the free trial.

Static QR Codes do not expire.
Account upgrades can be made at any time, regardless of how long your free trial has been expired.