Im filing late, and want to ensure all penalties and fees are included before I file. How do add the penalty for filing late.

Any penalties and interest for the late payment of the taxes owed and the late filing of the tax return will be calculated by the IRS once the IRS has received the tax return and payment for the taxes owed.  The IRS will send you a bill in the mail to pay the penalties and interest.

Penalties and interest are not entered on a tax return nor are they deductible on a tax return.

There is no penalty for filing after the due date if the return is being filed for a tax refund.

The penalty for filing late is 5% of the total tax assessed that was not paid when due. It is charged each month or part of a month the return is late, for up to 5 months. The penalty for paying late is initially ½% of the unpaid tax shown on the return. It is charged each month or part of a month following the payment due date until the tax is paid. The penalty increases to 1% of the unpaid tax for any tax that is not paid within 10 days after we issue a notice of intent to levy. However, the total penalty cannot exceed 25%. When both penalties are charged for the same month, we reduce the penalty for filing late by the penalty for paying late for that month.

Interest — We are required by law to charge interest
when you do not pay the amount you owe on time.
Generally, we charge interest from the due date of
your return (regardless of extensions) until you pay
the amount you owe in full, including all interest and
any penalty charges. Interest rates are variable and
may change quarterly.

None of these answers address the question. I also want to know how to add the late fee into my payment.

@jeff_elbel You cannot add the late fee yourself, nor will TurboTax calculate it for you.  If you are filing a late tax return with tax due, then when the IRS receives your return with the payment of the tax due shown on the return, the IRS will bill you later for the late penalty and interest that the

IRS

will calculate.