State tax filing

i used the 2019 turbotax and it failed to direct me to the correct line on the 2018 oregon tax return form to get my tax liability for 2018. subsequently i did not get my kicker refund added to my 2019 return. i believe this is turbotax software fault. how do i amend my return and where are the specific  and correct instructions on how to get my kicker refund using the free edition turbotax software?