Since you are "independent" (can't be claimed as a dependent by someone else), you do not have to file a tax return, if you have under $13,850 of reportable income, unless you have more than $400 of self employment income.
For those who can be claimed as a dependent, the filing threshold is as little as $1250 on investment income.
@SBM19 said " I'm sure that things have been bought/sold through their algorithm last year"
You should receive a form 1099-B for that activity. If your total gains for the year are less than $13,850, you do not need to file (unlikely with only $2000 invested). But, one risk with robo investing is that enough activity is generated to waive a red flag at the IRS. Again, unlikely with only $2000 invested and easily explained if you do receive an IRS notice (unlikely).
