No, the chassis fan is for......well a chassis (case) fan.
On smaller boards, there's sometimes only one.... and located where that one is. That's because most people in smaller builds opt for a single exhaust fan at the rear.
The GPU does not attach to a fan header.
If you have two, you'll need some kind of splitter or hub.
Something as basic as this:
https://www.newegg.com/Product/Product.aspx?Item=9SIABYB4YA6092&cm_re=fan_splitter-_-9SIABYB4YA6092-_-Product
Or, for an all black sleeved option, it's still <$4 https://www.newegg.com/Product/Product.aspx?Item=N82E16812162059&cm_re=fan_splitter-_-12-162-059-_-Product