I an sure he is your dependent and dependents cannot get the stimulus.
2020 Filing requirements for dependents.
Single dependents— (Not age 65 or older or blind)
You must file a return if any of the following apply.
1. Your unearned income was more than $1,100.
2. Your earned income was more than $12,400.
3. Your gross income was more than the larger of—
a. $1,100, or
b. Your earned income (up to $12,050) plus $350.
Or Dependent had net earnings from self-employment of at least $400.
However, if any tax was withheld, then Dependent might want to file anyway to get a refund of the tax withheld.
Also, a person that CAN be a dependent cannot claim him/her self and must check the box that says that another taxpayer can claim them (whether or not that taxpayer actually claims him/her).
Note: your state filing requirements might be different than the federal.
You don't include their income on your return. It would only go on their return if they are required to file one. To file a separate return for your dependent you need to set up a new account. Online is only good for one return per account. You can use the same email address for 5 accounts. They can probably use the Free Edition. How to start a new online return
https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-start-another-return-in-turbotax-online/00/25596
Be sure on their return they check the box that says they can be claimed on someone else’s return. If their only income is W2 and under 12,400 they do not have to file a return except to get back any withholding taken out.
Filing requirements for a dependent
https://ttlc.intuit.com/community/children-dependents/help/do-i-need-to-file-my-own-taxes-if-i-m-a-dependent/00/26111