I wanna create visuals for stock site with 3D software. Can I use a %100 free font on design and put it sale on stock site? Is it allowed?

ask the font creator

What if I ask the creator of every font I use and there is no answer? What if he answers too late? If it says 100% free, what is it for completely free?

Thanks anyway I've googled and find some commercial free fonts somewhere. Thanks for be interested