I erroneously sent an extra check to the IRS for $2,959 dollars. they cashed the check, How do I get back my $2,959 overpayment?

In July, I owed the IRS $ 7,312 for 2019. in addition to the $7,312 check, I erroneously sent an extra check to the IRS for $2,959 dollars. they cashed both checks, How do I get back the $2,959 overpayment?