That depends----will they get a W-2 with any federal or state tax withheld and want to seek a refund of that tax? Or did they work as an independent contractor?
MY DEPENDENT HAD A JOB
If your dependent has a W-2 for his after-school job, summer job, etc. you do not include the information on your own return. You can still claim your child as a dependent on your own return. He/she can file his own return for a refund of some of his withheld wages (he won’t get back anything for Social Security or Medicare), but MUST indicate on it that he can be claimed as a dependent on someone else’s return. (Supervise this closely or prepare it for him!)
If your dependent’s earnings were over $400 and were reported on a 1099Misc or 1099NEC then he must file a return and pay self-employment tax for Social Security and Medicare.
You might also want to use free software from the IRS Free File versions:
https://apps.irs.gov/app/freeFile/
Depends on the type of income.
If the income is received for wages reported on a W-2, they do not need to file since they are below the minimum filing requirements.
If the income is from self-employment they are required to file a tax return since the amount of SE income is $400 or more. They report the SE income and expenses on a Schedule C which is part of the federal tax return, Form 1040. If they do have to file then make sure they indicate on their tax return that they can be claimed as a dependent.