You will receive the remaining Child Tax Credit on your 2021 federal tax return.
You file the 2021 tax return using the address where currently live and receive your mail.
The Child Tax Credit is entered on your federal tax return Form 1040 on Line 28. It is added to your other tax payments, it is not a separate refund. Your Total taxes from Line 24 are subtracted from your Total tax payments on Line 33. If you have an overpayment then that is entered on Line 34 as your federal tax refund.