I used the wrong return

Uh oh....do you mean you e-filed it already with the wrong W-2?

Please help me with my 2018 return tax

Please respond back to let us know what exactly we can help you with concerning your 2018 tax return. 

I e-filed the 2019 return on 2-24-2021 instead of the 2020 return. The return was accepted. How can this be fixed? Is there anyway to have the 2019 filing rejected? If not, how can I file an amended return.

Since your e-filed return has been accepted, you can amend your return to correct the error. Please see below for more information.

https://ttlc.intuit.com/community/amending/help/how-to-amend-change-or-correct-a-return-you-already-filed/00/25588