Add another add to cart

Hi,

Actually I try to find a solution, i would to add another button “add to cart” on product page ? Is it possible to add by snippet code without Elementor or any plugin ?
My idea is to get two buttons “add to cart” on the product page, one in the form of sticky (with this quantity input) which is already done with the CSS and one “fixed” in mobile device.

Any idea ?

Thank you.

The page I need help with: [log in to see the link]