I work a couple of months in 2020 and I got a W-2 form saying that I'm getting $9 back from taxes do I have to file to get my stamp third stimulus check

[MayaD]

The IRS uses 2019 or 2020 tax returns to determine eligibility for your third stimulus check. You don't have to file your 2020 to receive the third stimulus check unless your 2019 income is above the income limit.  

The income limits to get a full check are $75,000 for single filers and $150,000 for married joint filers. You can get a reduced check if you earn up to $80,000 or $160,000, respectively.