Add to cart button not showing on mobile

Hi, im trying to show the ADD TO CART (named AGREGAR AL CARRO, since the webpage is intended to be in Spanish) on mobile devices but i just cant figure it out. Ive tried several different codes using CSS and additional php but I havent been able to make it work. If you see the link (https://tucafecito.cl/product/cafe-en-grano-exquisit-1kg/) you will be able to view the product. Ive also attached a screen shot taken from an iPhone 11, which does not show the button in question.

Thanks!