No Labels is a group that calls itself centrist and says it is not a political party. They are a group that's looking into possibly running their own presidential candidate in 2024.
And since they're not a political party, they don't have to reveal their donors.
This is very convenient since they've received tens of millions of dollars, some of them from Republican billionaire Harlan Crow (yeah, the same dude that gives gifts to Supreme Court Justice Clarence Thomas).