NO

Each tax year has to be filed separately using the forms for the specific tax year.  They cannot be combined in any way--do not even put them in the same envelope when you mail them.  Software for past years is available back to 2017.  Any earlier years can only be prepared on paper forms by hand--and those refunds have been forfeited now.

The current online program can only be used for a 2020 return--no other year.  And if you did not file a 2019 return you will have trouble e-filing 2020.  When it asks for your 2019 AGI try using zero.  If zero does not work then you have to print, sign and mail 2020.

Online preparation and e-filing for 2017, 2018 and 2019 is permanently closed.

To file a return for a prior tax year

 If you need to prepare a return for 2017, 2018, or 2019 you can purchase and download desktop software to do it, then print, sign,  and mail the return(s)

https://turbotax.intuit.com/personal-taxes/past-years-products/

You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.

Remember to prepare your state return as well—if you live in a state that has a state income tax.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

Note:  The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac.  It cannot be used on a mobile device.

If you are getting a refund, there is not a penalty for filing past the deadline.  If you owe taxes, the interest/penalties will be calculated by the IRS based on how much you owe and when they receive your return and payment. The IRS will bill you for this; it will not be calculated by TurboTax.

Since you are filing a late 2019 return, the IRS will not have a 2019 AGI in the system for you.  When the 2020 software asks for your 2019 AGI so that you can e-file 2020, use “zero.”  If you cannot e-file by using zero then you will have to print, sign and mail your 2020 return.

Ok thank you and

can you also answer this 

So earlier today I filed my 2020 taxes and refund was like $100 so I went back and looked and I answered yes to being a dependent but said no , someone plans to claim me as their dependent. 
my mom did her taxes last month on the 7th of Feb and claimed me as her dependent because I am . Now I have to wait till March 25th to amend but will my mistake affect her tax return and her ability to get the new stimulus that’s suppose to roll out this month? 

No your return will not affect Mom because she already filed and her return has been accepted.   The problems occur when a dependent files first and says NO to the question about being a dependent----then the parent who tries to e-file gets rejected and has to file by mail.

If you said yes to the question about whether you can be claimed as a dependent then you should both be fine with no worries about amending.