It's a Scam-the Government does not randomly call people and award them thousands of dollars because they are a good citizen, pays their bills on time or haven't filed bankruptcy. In addition, these criminals will have you pay a (mystery) fee, maybe $250-$500 or so for taxes or processing or some other made up thing.
So they steal your money and you NOTHING. You get no free money.
https://www.consumer.ftc.gov/articles/0113-government-grant-scams