Since you have already submitted your return to IRS, you cannot cancel the return.  Instead, you will need to do an amendment.  See instructions below.

To amend from Form 1040 to 1040NR,  here are the steps:

-If you are considered as a nonresident, as TurboTax does not support the NR form, you are recommended to use our  affiliated partner, Sprintax  to complete your 1040-NR filing.  

1.  Download the Form 1040-X from IRS website ( see below).  On the front page of Form 1040-X, enter your name,                    current address, and social security number (SSN) or IRS individual taxpayer identification number (ITIN)

2.  Do not enter any other information on page 1.  

3.  Do not complete Parts I or II on page 2 of Form 1040X.

4.  Enter in Part III the reason why you are filing Form 1040X.

5.  Complete a new or corrected form 1040-NR by using Sprintax, see above.

6.  Across the top of the 1040-NR, write “Amended”

7.  Attach form 1040-X to the back of Form 1040X

For more information, see:

https://www.irs.gov/pub/irs-pdf/f1040x.pdf  - form

https://www.irs.gov/pub/irs-pdf/i1040x.pdf  - instructions

page 5 under Residents and Nonresidents

Filed wrong tax return, as F1-OPT  for federal and state! Also got all the refunds including the stimulus money for COVID-19! How to fix it?

Please see LinaJ's instructions above for how to amend your federal return.  You will need to complete your 1040NR with Sprintax , print it, attach it to your 1040X  before mailing.

Please go to your state website for information on how to amend your state return.  Maybe Sprintax can help you amend your state return.

Please see the following IRS Topic Returning an Erroneous Refund so you can return the stimulus payment you received.

I too did the same. Please share the details once u rectify that .