1) Sign in with your Premium account.
2) Download the backup file
On the Premium page, you will find a list of your planners, from which you can download the backup file of the planner you want to restore.
3) Restore from a backup
When you create a new planner by clicking on the "+" button in the planner management page, you can create a new planner from the backup file.
Please select the backup file that you downloaded in step 2 above.
4) Delete unwanted planners
When you restore your planner from the backup, you will have two identical planners in the cloud temporarily.
Please make sure that the restored planner is in good condition and delete the old planner from the list of planners in the Premium page.