Where can I enter to deduct my insurance premiums as an expense that I paid for while unemployed?

You are posting from online software---you do not have direct access to the forms so you cannot just enter it on a form or line number.   If you paid medical insurance out of pocket you can enter it as a medical expense---it is very difficult to use medical expenses as an itemized deduction.

MEDICAL EXPENSES

The medical expense deduction has to meet a rather large threshold before it can affect your return. The amount of medical (including dental, vision, etc.)  expenses that will count toward itemization is the amount that is OVER 7.5% of your adjusted gross income. You should only enter the amount that you paid in 2020—do not include any amounts that were covered by insurance or that are still outstanding.  Of course, your medical expenses plus your other itemized deductions still have to exceed your standard deduction before you will see a difference in your tax due or refund.

To enter your medical expenses go to Federal>Deductions and Credits>Medical>Medical Expenses