In Box 17 on the K1 for the owners, you use "V".
When the owner then puts this K1 into his/her 1040, after answering the other questions inputting the K1, they will get to Box 17 where they also put in "V". Assuming the answers to the other questions are inline with what is need to get the QBI deduction, it will pop into the 1040. Note: this only worked for me today (1/29/2020) when I updated TurboTax to pick up the latest. It wasn't finished last week.
