You cannot use IRS Form 5405, First-Time Homebuyer Credit and Repayment of the Credit on a 2018 tax return if you converted the home to a rental in 2013. The remaining credit had to be repaid on your 2013 tax return using the 2013 Form 5405. You need to amend the 2013 tax return and include Form 5405 with the federal amended return, Form 1040X.
TurboTax does not support tax year 2013.
IRS Form 1040X (2013) - https://www.irs.gov/pub/irs-prior/f1040x--2013.pdf
IRS Form 1040X (2013) Instructions - https://www.irs.gov/pub/irs-prior/i1040x--2013.pdf
IRS Form 5405 (2013) - https://www.irs.gov/pub/irs-prior/f5405--2013.pdf
IRS Form 5405 (2013) Instructions - https://www.irs.gov/pub/irs-prior/i5405--2013.pdf
