You misunderstood. Anyone at any age can have taxes owed. It depends on the income they received and the amount of tax payments that they paid (taxes withheld).
Just complete your tax return and if you are being claimed as a dependent by your parent's or someone else then you indicate on your tax return that you are a dependent.
A Dependent filing Single -
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 $12,200.
3. Your gross income was more than the larger of—
a. $1,100, or
b. Your earned income (up to $11,850) plus $350.
