Provided the 2018 return was prepared within your account with PTO, simply create a new return for 2019 and you will be prompted to choose which 2018 return you want to roll over from.

Hi Are you looking for import 2018 tax return from other sytem than PCO into PCO?

I have done once imported from 2018 Turbotax to 2019 PCO. You can search that or ask customer service give you instruction. 

But what i was looking for was import (convert) 2018 turbotax to 2018 PCO, so I can have a base year return match to what was filed in other system.

Since then when I have new customer, I will manually enter their prior year tax as filed in PCO.