Last night I completed a tax return for 2020 and for some reason it is coming up as a return for 2021

Please make sure that you are logged into the right year of TurboTax Online. The web address for 2020 is: https://ww1.2020.turbotaxonline.intuit.ca/  

If you have accidently prepared your return using the wrong year, you’ll need to start over in the correct year. The is no way to change the tax year of a return.