TurboTax won't allow me to file a form 5404 and pay $180 to pay off a first-time home buyer credit. Very frustrating!

form 5405. did you change homes in a previous year? if so, the unpaid amount was due that year.

TurboTax will not allow you to file form 5405 unless you moved out of your home (sold it or otherwise moved out) during 2020. If you sold or moved out in a previous year, you will have to amend your tax return for that previous year to include form 5405.  If you only owe an annual repayment, you are not required to file form 5405. You just include the repayment on your tax return.