Go into your account and return.
Click Income & Expenses (in TurboTax Self-employed)
Scroll down to "Self-employment income and expenses" Click Review
Click Review next to the business name
Scroll down and click "Add expenses for this work"
Scroll down and click "Less common expenses" if needed
Scroll down and click the radio button for "Building or land rental"
Scroll all the way down the page and click Continue
Enter the rent expense