It's Business Income. It's not treated any differently (with those exceptions you would need to research, as noted). They got it because they are in business, and for being in business, and for the same reason as if they did that business.

I totally understood it's business income. If it goes to SCH C, QBI and SE tax appear on the client return while it was not income type which makes QBI and SE tax since it is a grant. So, I am confused how to enter this amount to which line on SCH C and where would be the place to enter Payer's info.