How to export all QB data out of QBO Essentials?

Any specific goal? You can utilize an exporter tool.

https://transactionpro.grsm.io/qbo

or purchase a 3rd party service if you need to convert your data to another brand.

I can share a few details to export our QuickBooks Online data, @uwe_tti.

I know how much you want to save a copy of your QuickBooks Online data by exporting them. However, we're unable to export all the data at once. In this case, I recommend following Fiat Lux - ASIA's suggestion. You can use a third party application to export the data out of your QuickBooks Essential account.

On the other hand, we can export chunks of data like lists of customers, vendors, and employees. We also include reports like general ledger, profit and loss, balance sheet, trial balance, and journal. For more information, feel free to read this article: Export reports, lists, and other data from QuickBooks Online.

Let me know if you have additional questions about moving your data out of QBO. The Community will always help you here. Take care always!