Contributions can happen retroactively, conversions cannot.

For 2020 you have non-deductible IRA contributions reported on Forms 8606 (one for TP, one for SP).  For 2021 you'll have a 1099-R to report as a Roth IRA conversion.  For now your 8606 forms will "end" with $7,000 of basis.  Next year that basis carries forward and will get applied to the distribution, making it non-taxable (again, on the Form 8606 but in a different section).