Yes that is correct. You can contribute additional monies, up to the limit, typically through EFT or check directly to your HSA provider and you will be able to deduct that on your 2024 tax return.
One item to note for the future is that when you make personal contributions to your HSA, you do not get a break on payroll tax, as you would with a payroll contribution. So in the future if it is possible to make the contributions via payroll, that will benefit you.
