How do I estimate 2021 taxes in TT 2020?

My wife just changed employers and will for the first time be 1099 contractor, not receiving a w-2 nor having any withholding.  How do I estimate taxes using TurboTax 2020 Premier - CD for Mac.  I cannot find a way to access Other Tax Situations as I have read in other posts, or anything that would help me figure out how to estimate taxes I should be withholding and/or paying to the IRS now.