Thank you for contacting us about backing up QuickBooks Online (QBO), marius-wehmeyer.
QBO automatically backs your data up in our cloud server every night. It's to always ensure to keep your data safe and secure. For more details, check out this article: Do I need to back up my data with QuickBooks Online?
You may want to export reports and lists out of QuickBooks if you need a copy of them. Here's how:
Go to the Settings ⚙ icon from the toolbar.
Under Tools, select Export Data.
On the Reports tab, set the date range.
Add or remove items from the Reports and Lists tabs by toggling the slider.