After your free trial ends, your account remains accessible, and all data and progress are retained. However, you won't be able to view this data, and it will be displayed as depicted 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.