Hi Lee,
Thanks for posting in the Community!
The expense claims option is currently available in the QBO Advanced version. Kindly check your subscription plan to verify. To check your plan, go to Settings and click on Billing & Subscription page.
If you wanted to use and assign users with expense claims option, you will need to upgrade your subscription to Advanced version. Check this link to see features and pricing for each plan https://quickbooks.intuit.com/au/pricing/.
You can check this link to learn more about: Set up employee expense management in QuickBooks Online Advanced.
Post again in the Community if you have other questions about QBO.