Hi there, natalie4.
It's a pleasure to see you here in the Community. I'm here with some insight to provide regarding this matter.
At this time, QuickBooks Online doesn't have the option to track the expiration date of your items. For additional insight about this, you can visit this article: Add, edit, and delete items
I can see how having this option could help you keep track of your items and make sure that you have a sufficient quantity all the time. Rest assured, I'll be sending feedback to our Product Development Team based on this interaction. After all, enhancements to QuickBooks functionalities are largely the results of feedback provided by users, such as yourself.
Lastly, I don't want you to go empty-handed. You may want to visit our Apps Center. In here, you can look for a third-party app, that will help you keep track of the expiration, and integrate it with QuickBooks.
Please don't hesitate to keep in touch if there's anything else I can do for you in the meantime. I always have your back and am always happy to help. Have a great day!