"I tried to get this answer earlier."

Yes, we've been working on it, here:

https://proconnect.intuit.com/community/lacerte-tax-discussions/discussion/backdoor-roth/00/143990

You just asked the very same people that you already asked. This is not Customer Support or Tech Support. No one is just standing by to take your call; your peers are also working today. Volunteering to be helpful here means taking away from other work. And that means other work takes away from trying to be helpful here.

Their Roth Basis has no impact on what you asked. On you other topic, it's been noted there is nothing special about this. you have a nondeductible contributions and a conversion, which happens to be nontaxable because there are no earnings.

Here are the IRS links to the instructions and the Form:

https://www.irs.gov/pub/irs-pdf/i8606.pdf

https://www.irs.gov/pub/irs-prior/f8606--2020.pdf

Your input screens should carry over to the forms, so make sure you have T and S, of course.