The filing status that you want is married filing separately, not married filing single.
Did you already file your tax return as single? If so, you will have to file an amended return (Form 1040-X) to change it. The IRS just made a change, a few weeks ago, to allow an amended return to be e-filed with a change of filing status. I don't know if TurboTax has been updated to allow it, or whether they will allow it at all this year. But you have to file the amended return in any case. So try to e-file it. If it doesn't work you'll have to print the amended return, sign it, and file it by mail.
See the following FAQ for instructions to amend a 2021 tax return that you filed with TurboTax.
How do I amend my 2021 return?
Before you start to amend your return in TurboTax Online, be sure to download a PDF of your original tax return and save it on your own computer. Once you amend it, you will no longer be able to access the original in TurboTax.
It normally takes the IRS 16 weeks to process an amended return. But they are severely backlogged this year, so expect it to take much longer than that.
Don't file the amended return until your first return has been accepted and you have received the original refund.
If you filed a state tax return, you will have to amend that as well.
