I appreciate you choosing QuickBooks Online (QBO) as your accounting partner, @leoni. I'll share some information on how you can import purchase orders into the program. 

Currently, the option to import purchase orders into QBO is unavailable. That said, you have enter them into the program manually. Here's how:

1. Log in to your QBO account.
2. Next, select the Gear icon and choose Purchase Order.
3. From there, enter the needed details. 
4. Once done, click the Save and close button to record the transaction. 

For reference, check out this article: Create and send purchase orders in QuickBooks Online.

On the other hand, you can also look for a third party applications that has this feature and can be integrated with QBO. Let me guide you on how:

1. Go to the QuickBooks Apps Store page.
2. Next, enter a keyword of the app you need. Example: Import purchase order.
3. The page will show a list of apps based on your search.
4. To check which one is applicable to your business, just select it and go to the Overview tab to view their description. 

I also included this resource that you can use as a guide in handling other vendor transactions in your account: Manage Suppliers and Expenses for QBO-International.

I'm always here ready to lend a hand if you have other concerns about importing purchase orders in QuickBooks. Just leave a reply below and I'll get back here to help. Have a good one.