If you used TurboTax Online to complete and file your 2020 tax return, you can access a copy by following the steps in this TurboTax help article: How do I access a prior-year return?
If you used TurboTax CD/Download software to complete and file your return, then TurboTax would not have a copy as your tax return would be stored locally on your computer or storage device.
You can also request a copy of your tax return from the IRS, however, if you have an immediate need, you can get a copy of your tax transcript from the IRS. See How do I get a copy of my tax return or transcript from the IRS? for more information.