The most desired action on product pages is for users to add your product to the cart. That’s why a prominent CTA is one of the most essential parts of a product page.
Without a CTA, the user experience would reach a dead end when shoppers find their desired product.
However, your store shouldn’t overload the shoppers with CTA’s. The main call to add the product to cart is enough and you don’t want to distract shoppers with other options before they click it.
You should use ,,Buy now” CTA if you want to sell one product or lead the customer through a product funnel; if you want your customer to add more products to their cart and encourage them to browse your store for a longer time, your CTA should say ,,Add to cart”.