I'm happy to share information about sales orders in QuickBooks Online (QBO), @Timi1.
For the time being, QBO doesn't have a Sales Order option. However, you may need to integrate QuickBooks Commerce to fulfill items on a sales order manually and create partial shipments.
When you create a sales order, it goes through stages that update the stock level correspondingly. For a quick summary of the difference between the stock levels that are showing in QuickBooks Commerce, please refer to this article: Various Stock Levels in Quickbooks Commerce.
Also, to learn more about sales order status and how you can manage them in in QuickBooks Commerce, I'd recommend checking out these articles:
If you wish to learn more about sales orders and managing income transactions in QuickBooks, keep me posted in the comments below. I'll gladly help. Take care, and I wish you continued success, @Timi1.