can i make a back up?

Yes, you can create a backup copy of your company file if you have a QuickBooks Online Advanced subscription. However, you will need to use a third-party migration tool to restore the backup into another accounting platform.
 

You can follow the steps in this article to create a backup: Back up and restore your QuickBooks Online Advanced company.
 

If you are using QuickBooks Online Plus or Simple Start, you can manually back up your company file by exporting your reports and lists: Export your QuickBooks Online data.
 

After that, you can use the exported data as a reference when setting up your new accounting system.
 

Let us know if you need anything else. We're here to help.

Do you have QBO US version or Global version?