Determing a child's MAGI

[needaanswer]

How do I find the MAGI for a 7 year old child who has to file an income tax return? I have to have the MAGI to input on my son's tax return.  The popup says "Your dependent child's MAGI can be calculated by adding any amount reported on Form 1040 lines 2a to the amount on line 8b". How do you do find the MAGI when there is nothing on line 2a and no line 8b on form 1040. Many thanks for any assistance.

[Tileworks]

The current description is for a previous tax year and hasn't been updated. It should read "by adding line 2a to line 9". 

In the 2019 tax year, line 8b was the adjusted gross income. For 2020 however, this is line 9. TurboTax failed to update the description accordingly.