Deductions & credits

Type 'schedule c' in the Search area,  then click on 'Jump to schedule c'.

If you have already entered info for your Business, choose EDIT.   If not, you will be asked for details on your business.

Enter your Business Income, then your Business Expenses, where you can deduct business rent  you paid.

In TurboTax Online, you may need to click on 'Show More' to have Building Rent display. 

Click this link for more info on Reporting Business Expenses.