You only need a 8606 if you made a non-deductible Traditional IRA contribution or took a distribution for Traditional IRA with a non-deductible basis.
If you have not made any non-deductible contributions then no 8606 is needed.
Are you sure that I wouldn't need to file a Form 8606 if I have no non-deductible contributions? The instructions for the 2020 Form 8606 state
Who Must File
File Form 8606 if any of the following apply.
...
• You converted an amount from a traditional, SEP, or SIMPLE IRA to a Roth IRA in 2020.
• You received distributions from a Roth IRA in 2020 (other than a rollover, recharacterization, or return of certain contributions—see the instructions for Part III, later).
Those two bullet points don't mention anything about non-deductible contributions, although the bullet points before them do.
I have converted amounts from traditional IRAs in 2020 and in several previous years, and I have taken a distribution from a Roth IRA in 2018. It seems like those actions fit the bulleted requirements, at least for the 2020 tax year.
