You can but it depends on if you lived with your spouse at any time during the year and your MAGI.
Go to this IRS website for Roth IRA contribution information - https://www.irs.gov/retirement-plans/plan-participant-employee/amount-of-roth-ira-contributions-that...
This info is for Roth IRA's. I'm wanting to know if tax status matters for Roth 401k. I've read elsewhere it does not.
Sorry about that. For a Roth 401(k) -
You can contribute a maximum of $19,500 in 2020 and 2021 to a Roth 401(k)—the same amount as a traditional 401(k). If you’re aged 50 or older, you can contribute an extra $6,500 as a catch-up contribution. These limits are per individual; you don’t have to consider whether you’re married or single.