July 2021- Dec 2021
IRS child tax credit  Not received for 1 child out 2 children. 

July to dec 2021 = 6 months 
each month IRS paid = 500$ for only 1 child instead of 2

total amount paid for 1 child  =  6month x 500$ = 3000$
2nd Child  = 3000$ need to pay (need to claim)