Hello there, @bschimanski.

Let me guide you on how to have the Manage categories option in QuickBooks Online by doing some basic troubleshooting. 

Let's begin by logging in to your QuickBooks account using a private browser since this mode prevents browsing history from being stored.

You can clear the cache that helps deletes any necessary content saved and enables your browser to function more efficiently. 

These are the keyboard shortcuts you can use for private window:

• For Chrome, press Ctrl + Shift + N.
• For Internet Explorer or Firefox, hit Ctrl + Shift + P.
• For Safari, hold down Command + Shift + N.

For additional reference, I've attached this article you can use about categorizing products and services to keep things organized: Group your products and services into different categories.

 Please let me know if there's anything I can help you with QuickBooks. I'm always around whenever you need help.