What if when I did e-file I chose pay my tax balance by check, but I then changed my mind and paid online via pay1040.com

[zhchong0623]

What if when I did e-file I chose pay my tax balance by check, but I then changed my mind and paid online via pay1040.com

Can I just disregard the request "mail your completed form 1040-v with included payment of xxx made payable to United States treasury by may 17,2021"? because I already paid my full balance online? 

[fanfare]

If your tax is paid, discard the voucher.
OR
keep it as a souvenir.