Purchase Requests - how do I get Zoho Books Items to show up?

Purchase Requests - how do I get Zoho Books Items to show up?

In Zoho Expense Admin View > Settings > Modules > Items the items in Zoho Books can be viewed, leading one to believe these items are available in Zoho Expense, I assume for purchase requests. However when I attempt to raise a purchase request, only two items show up (and search brings up nothing). See screenshots. Is there something I need to do so all the items show up?

Thanks!