It is highly unlikely that TurboTax would support IRS Form 709 since it is not part of a personal tax return. It has to be filed separately from the Form 1040 and mailed to a different address than the Form 1040.
Gifts given to family members, friends or other individuals are not deductible. Gifts received are not taxable to the person who received the gift, and are not entered on a tax return.
If your gift exceeds the yearly limit ($17,000 per individual) imposed by the gift tax rules, then you will need to complete a Form 709 gift tax form and send it to the IRS, although it is very unlikely that you will owe any tax. In 2024 that yearly limit will increase to $18,000.
TurboTax does not support Form 709. It is not an income tax form and would not be included as part of an income tax return.
Here is a link to the form:
https://www.irs.gov/pub/irs-pdf/f709.pdf
https://turbotax.intuit.com/tax-tips/estates/the-gift-tax-made-simple/L5tGWVC8N