You may enter it under Supplies or you may enter it under Miscellaneous Expenses and enter your own Description. 

See the screenshots below.

Business assets with a useful life over a year are generally recorded under "Assets/Depreciation" on the Business Income and Expenses section.

To enter your business expenses: 

• Sign into your account and open your return by clicking the orange Take me to my return button.
• Type Sch C in the search/find bar and click search/find.
• Click on Jump to Sch C.
• Click on start/edit or Add Another Business.
• At the Your XXX Business screen, scroll down to Business Expenses, Other Common Business Expenses. Click Start/Edit. 
• On the Let's write off some business expenses screen, scroll down to Supplies or Miscellaneous Expense. 
• Continue with the onscreen interview.